Contents at a Glance
Introduction ........................................................1
Part 1: Getting Started with Excel Formulas
and Functions ......................................................5
CHAPTER 1: Tapping Into Formula and Function Fundamentals ..................7
CHAPTER 2: Saving Time with Function Tools .................................39
CHAPTER 3: Saying “Array!” for Formulas and Functions ........................55
CHAPTER 4: Fixing Formula Boo-Boos ........................................65
Part 2: Doing the Math ...........................................83
CHAPTER 5: CalculatingLoanPaymentsandInterestRates .....................85
CHAPTER 6: Appreciating What You’ll Get, Depreciating What You’ve Got ........105
CHAPTER 7: Using Basic Math Functions ....................................121
CHAPTER 8: Advancing Your Math ..........................................139
Part 3: Solving with Statistics ..................................161
CHAPTER 9: ThrowingStatisticsaCurve .....................................163
CHAPTER 10:UsingSignicanceTests ........................................203
CHAPTER 11:RollingtheDiceonPredictionsandProbability ....................213
Part 4: Dancing with Data ......................................231
CHAPTER 12: Dressing Up for Date Functions .................................233
CHAPTER 13: Keeping Well-Timed Functions ..................................251
CHAPTER 14:UsingLookup,Logical,andReferenceFunctions ..................261
CHAPTER 15: Digging Up the Facts ...........................................297
CHAPTER 16:WritingHomeaboutTextFunctions .............................311
CHAPTER 17:PlayingRecordswithDatabaseFunctions ........................337
Part 5: The Part of Tens .........................................353
CHAPTER 18: Ten Tips for Working with Formulas .............................355
CHAPTER 19: Ten Ways to Get Fancy with Excel ...............................369
CHAPTER 20:TenReallyCoolFunctions ......................................375
Index ...............................................................383
Excel® Formulas & Functions
Table of Contents v
Table of Contents
INTRODUCTION ...................................................1
AboutThisBook ...............................................1
Foolish Assumptions ...........................................2
Icons Used in This Book ........................................2
Beyond the Book ..............................................3
Where to Go from Here ........................................3
PART 1: GETTING STARTED WITH EXCEL FORMULAS
AND FUNCTIONS ..................................................5
CHAPTER 1: Tapping Into Formula and Function
Fundamentals .............................................7
Working with Excel Fundamentals ...............................8
Understandingworkbooksandworksheets ....................8
IntroducingtheFormulastab ...............................11
Workingwithrows,columns,cells,ranges,andtables ..........13
Formatting your data ......................................18
Getting help ..............................................19
Gaining the Upper Hand on Formulas ...........................20
Enteringyourrstformula ..................................20
Understanding references ..................................22
Copyingformulaswiththellhandle .........................25
Assemblingformulastherightway ..........................26
Using Functions in Formulas ...................................28
Looking at what goes into a function .........................30
Arguing with a function ....................................31
Nesting functions ..........................................34
CHAPTER 2: Saving Time with Function Tools .....................39
Getting Familiar with the Insert Function Dialog Box. . . . . . . . . . . . . . .39
Finding the Correct Function ...................................41
Entering Functions Using the Insert Function Dialog Box ...........42
Selecting a function that takes no arguments ..................43
Selecting a function that uses arguments .....................44
Enteringcells,ranges,namedareas,andtablesas
function arguments ........................................47
GettinghelpintheInsertFunctiondialogbox .................50
UsingtheFunctionArgumentsdialogboxtoeditfunctions ......50
Directly Entering Formulas and Functions ........................51
Entering formulas and functions in the Formula Bar ............51
Entering formulas and functions directly in worksheet cells .....52
vi Excel Formulas & Functions For Dummies
CHAPTER 3: Saying “Array!” for Formulas and Functions ........55
Discovering Arrays ............................................56
Using Arrays in Formulas ......................................57
WorkingwithFunctionsThatReturnArrays ......................61
CHAPTER 4: Fixing Formula Boo-Boos ...............................65
Catching Errors As You Enter Them .............................65
Getting parentheses to match ...............................66
Avoiding circular references ................................68
Mendingbrokenlinks ......................................70
Using the Formula Error Checker ............................72
Auditing Formulas ............................................75
Watching the Watch Window ...................................78
Evaluating and Checking Errors .................................79
Making an Error Behave the Way You Want ......................81
PART 2: DOING THE MATH .....................................83
CHAPTER 5: CalculatingLoanPaymentsandInterestRates ....85
Understanding How Excel Handles Money .......................86
Goingwiththecashow ...................................86
Formatting for currency ....................................86
Choosing separators .......................................88
Figuring Loan Calculations .....................................90
Calculating the payment amount ............................91
Calculating interest payments ...............................93
Calculating payments toward principal .......................94
Calculatingthenumberofpayments .........................96
CalculatingthenumberofpaymentswithPDURATION .........98
Calculating the interest rate .................................99
Calculating the principal ...................................101
CHAPTER 6: Appreciating What You’ll Get, Depreciating
What You’ve Got ........................................105
Looking into the Future ......................................106
Depreciating the Finer Things in Life ...........................108
Calculating straight-line depreciation ........................110
Creating an accelerated depreciation schedule ...............111
Creating an even faster accelerated depreciation schedule .....113
Calculating a midyear depreciation schedule .................114
Measuring Your Internals .....................................116
Table of Contents vii
CHAPTER 7: Using Basic Math Functions ..........................121
Adding It All Together with the SUM Function ...................121
RoundingOutYourKnowledge ................................126
Just plain old rounding ....................................126
Roundinginonedirection .................................128
Leaving All Decimals Behind with INT ..........................133
LeavingSomeDecimalsBehindwithTRUNC ....................134
Looking for a Sign ...........................................135
Ignoring Signs ...............................................137
CHAPTER 8: Advancing Your Math ..................................139
Using PI to Calculate Circumference and Diameter ...............140
GeneratingandUsingRandomNumbers .......................141
Theall-purposeRANDfunction .............................141
PreciserandomnesswithRANDBETWEEN ...................143
OrderingItems ..............................................145
Combining .................................................147
RaisingNumberstoNewHeights ..............................147
MultiplyingMultipleNumbers .................................149
UsingWhatRemainswiththeMODFunction ....................150
Summing Things Up .........................................152
UsingSUBTOTAL .........................................152
UsingSUMPRODUCT ......................................154
Using SUMIF and SUMIFS ..................................156
Getting an Angle on Trigonometry .............................159
Threebasictrigonometryfunctions .........................159
Degrees and radians ......................................160
PART 3: SOLVING WITH STATISTICS .........................161
CHAPTER 9: ThrowingStatisticsaCurve ...........................163
GettingStuckintheMiddlewithAVERAGE,MEDIAN,andMODE ...164
Deviating from the Middle ....................................169
Measuring variance .......................................170
Analyzing deviations ......................................172
Lookingfornormaldistribution ............................174
Skewing from the norm ...................................179
Comparing data sets ......................................181
Analyzing Data with Percentiles and Bins .......................185
QUARTILE.INCandQUARTILE.EXC ..........................186
PERCENTILE.INCandPERCENTILE.EXC .......................187
RANK ...................................................189
PERCENTRANK ...........................................190
FREQUENCY .............................................191
viii Excel Formulas & Functions For Dummies
MINandMAX ............................................195
LARGEandSMALL ........................................196
Going for the Count .........................................198
COUNTandCOUNTA .....................................198
COUNTIF ................................................198
CHAPTER 10:UsingSignicanceTests ...............................203
Testing to the T .............................................204
ComparingResultswithanEstimate ...........................208
CHAPTER 11:RollingtheDiceonPredictionsandProbability ...213
Modeling ...................................................214
Linear model ............................................214
Exponential model .......................................214
GettingItStraight:UsingSLOPEandINTERCEPTto
DescribeLinearData .........................................215
What’sAhead:UsingFORECAST,TREND,andGROWTH
to Make Predictions .........................................219
FORECAST ...............................................219
TREND ..................................................221
GROWTH ................................................223
UsingNORM.DISTandPOISSON.DISTtoDetermine
Probabilities ................................................225
NORM.DIST ..............................................225
POISSON.DIST ...........................................227
PART 4: DANCING WITH DATA ................................231
CHAPTER 12: Dressing Up for Date Functions ......................233
Understanding How Excel Handles Dates .......................233
Formatting Dates ............................................235
Making a Date with DATE .....................................236
BreakingaDatewithDAY,MONTH,andYEAR ...................238
Isolating the day .........................................239
Isolating the month .......................................240
Isolating the year .........................................241
Converting a Date from Text ..................................242
FindingOutWhatTODAYIs ...................................243
Countingthedaysuntilyourbirthday .......................244
Counting your age in days .................................244
Determining the Day of the Week ..............................245
Working with Workdays ......................................246
Determining workdays in a range of dates ...................246
Workdays in the future ....................................248
Calculating Time Between Two Dates with the DATEDIF Function ...249
Table of Contents ix
CHAPTER 13: Keeping Well-Timed Functions .......................251
Understanding How Excel Handles Time ........................251
Formatting Time ............................................252
Keeping TIME ...............................................254
Converting Text to Time with TIMEVALUE .......................254
DeconstructingTimewithHOUR,MINUTE,andSECOND ..........255
Isolating the hour ........................................256
Isolating the minute ......................................257
Isolating the second ......................................258
FindingtheTimeNOW .......................................258
CalculatingElapsedTimeOverDays ...........................259
CHAPTER 14: Using Lookup, Logical, and Reference
Functions .................................................261
TestingonOneCondition ....................................262
ChoosingtheRightValue .....................................267
Let’s Be Logical ..............................................269
NOT ....................................................270
ANDandOR .............................................271
XOR ....................................................273
Finding Where the Data Is ....................................275
ADDRESS ................................................275
INDIRECT ................................................279
ROW,ROWS,COLUMN,andCOLUMNS ......................279
OFFSET .................................................282
Looking It Up ...............................................284
HLOOKUPandVLOOKUP ..................................284
XLOOKUP ...............................................288
MATCHandINDEX ........................................289
FORMULATEXT ...........................................294
NUMBERVALUE ..........................................295
CHAPTER 15: Digging Up the Facts ...................................297
Getting Informed with the CELL Function .......................297
GettingInformationAboutExcelandYourComputerSystem ......302
Finding What IS and What IS Not ..............................304
ISERR,ISNA,andISERROR .................................304
ISBLANK,ISNONTEXT,ISTEXT,andISNUMBER ................306
Getting to Know Your Type ...................................308
x Excel Formulas & Functions For Dummies
CHAPTER 16: Writing Home about Text Functions ................311
Breaking Apart Text ..........................................311
Bearing to the LEFT .......................................312
SwingingtotheRIGHT ....................................313
Staying in the MIDdle .....................................314
Finding the long of it with LEN ..............................315
PuttingTextTogetherwithCONCATENATE ......................316
Changing Text ..............................................318
Making money ...........................................318
Turningnumbersintotext .................................320
Repeatingtext ...........................................323
Swapping text ............................................324
Giving text a trim .........................................328
Making a case ............................................329
Comparing, Finding, and Measuring Text .......................330
GoingforperfectionwithEXACT ............................331
Finding and searching .....................................332
CHAPTER 17: Playing Records with Database Functions .........337
PuttingYourDataintoaDatabaseStructure ....................338
WorkingwithDatabaseFunctions .............................339
Establishingyourdatabase ................................339
Establishingthecriteriaarea ...............................341
Fine-TuningCriteriawithANDandOR ..........................343
AddingOnlyWhatMatterswithDSUM .........................345
GoingfortheMiddlewithDAVERAGE ..........................345
CountingOnlyWhatMatterswithDCOUNT .....................347
FindingHighestandLowestwithDMINandDMAX ...............348
Finding Duplicate Values with DGET ............................349
BeingProductivewithDPRODUCT .............................350
PART 5: THE PART OF TENS ....................................353
CHAPTER 18: Ten Tips for Working with Formulas ................355
MasterOperatorPrecedence .................................355
Display Formulas ............................................356
Fix Formulas ................................................358
UseAbsoluteReferences .....................................359
TurnCalcOn/TurnCalcO ...................................359
Use Named Areas ...........................................361
Use Formula Auditing ........................................362
Use Conditional Formatting ...................................363
Use Data Validation ..........................................364
CreateYourOwnFunctions ...................................365
Table of Contents xi
CHAPTER 19: Ten Ways to Get Fancy with Excel ...................369
Calculating Data from Multiple Sheets ..........................369
Getting Data from the Internet ................................370
DeterminingtheNeededNumber .............................370
RemovingDuplicates ........................................371
GettingtotheLastRowofYourData ...........................372
Freezing Panes ..............................................372
Splitting a Worksheet ........................................372
Filling Cells .................................................373
Adding Notes to Cells ........................................373
GettingMoreInformationaboutaWorkbookorWorksheet .......374
CHAPTER 20: Ten Really Cool Functions .............................375
WorkwithHexadecimal,Octal,Decimal,andBinaryNumbers .....376
Convert Units of Measurement ................................377
Find the Greatest Common Divisor and the Least Common
Multiple ....................................................378
EasilyGenerateaRandomNumber ............................379
ConverttoRomanNumerals ..................................379
Factor in a Factorial ..........................................379
DeterminePartofaYearwithYEARFRAC .......................380
Find the Data TYPE ..........................................380
Find the LENgth of Your Text ..................................381
Just in CASE .................................................381
INDEX ..............................................................383
Introduction 1
Introduction
Excel worksheets are used in many walks of life: business, education, home
nances, and even hobbies (such as keeping track of your baseball-card col-
lection). In my house, we use Excel for a lot, from our taxes (boring!) to our
ever-growing recipe collection (yummy!). Often, I use Excel in place of a calcula-
tor. After all, Excel is like a calculator on steroids!
In the workplace, Excel is one of the most commonly used analysis and reporting
tools. Financial statements, sales reports, inventory, project scheduling, customer
activity — so much of this stu is kept in Excel. The program’s capability to
manipulate and give feedback about the data makes it attractive. Excel’s exibility
in storing and presenting data is like magic.
About This Book
This book is about the number-crunching side of Excel. Formulas are the keystone
to analyzing data— that is, digging out nuggets of important information. What
is the average sale? How many times did we do better than average? How many
days are left on the project? How much progress have we made? That sort of thing.
Formulas calculate answers, straight and to the point. But that’s not all. Excel has
dozens of built-in functions that calculate everything from a simple average to a
useful analysis of your investments to complex inferential statistics. But you don’t
have to know it all or use it all; just use the parts that are relevant to your work.
This book discusses more than 150 of these functions. But rather than just show
their syntax and list them alphabetically, I assemble them by category and provide
real-world examples of how to use them alone, and in formulas, along with
step-by-step instructions and illustrations of the results.
Within this book, you may note that some web addresses break across two lines of
text. If you’re reading this book in print and want to visit one of these web pages,
simply key in the web address exactly as it’s noted in the text, pretending as
though the line break doesn’t exist. If you’re reading this as an e-book, you’ve got
it easy— just click the web address to be taken directly to the web page.
2 Excel Formulas & Functions For Dummies
Foolish Assumptions
I assume that you have a PC with Excel loaded. That’s a no-brainer! Nearly all the
material is relevant for use with earlier versions of Excel as well. I also assume
that you know how to navigate with a keyboard and mouse. Last, I assume that
you have used Excel before, even just once. I do discuss basics in Chapter1 but not
all of them. If you really need to start from scratch, I suggest that you read the
excellent Excel All-in-One For Dummies, by Paul McFedries and Greg Harvey (Wiley).
Other than that, this book is written for the Oce 2021 version of Excel, but just
between you and me, it works ne with older versions of Excel. There could be a
function or two that isn’t in an older version or works slightly dierently. But
Microsoft has done an excellent job of maintaining compatibility between ver-
sions of Excel, so when it comes to formulas and functions, you can be condent
that what works in one version works in another.
Icons Used in This Book
This book uses icons in the margins to grab your attention. Here’s a guide to what
the icons mean:
The Tip icon highlights information that’ll make your life easier— at least when
it comes to Excel.
The Remember icon marks some basic concept that you’ll want to keep tucked
away somewhere in your brain.
As it implies, the Warning icon is used for serious stu. This icon tells you to be
careful— usually because you can accidentally erase your data or some such hor-
rible event.
Once in a while, some tidbit is interesting to the tech-head types but not to any-
one else. I mark these paragraphs with the Technical Stu icon. You can read
these items or ignore them as you see t.
Introduction 3
Beyond the Book
In addition to the material in the print or e-book you’re reading right now, this
product also comes with some access-anywhere goodies on the web. Be sure to
check out the free online Cheat Sheet to nd the Excel order of operations, Excel
cell references worth remembering, common Excel error messages, and more. To
get the Cheat Sheet, simply go to www.dummies.com and type Excel Formulas &
Functions For Dummies Cheat Sheet in the Search box.
Where to Go from Here
Roll up your sleeves, take a deep breath, and then forget all that preparing-for-a-
hard-task stu. Using Excel is easy. You can hardly make a mistake without
Excel’s catching it. If you need to brush up on the basics, go to Chapter1. This
chapter is also the best place to get your rst taste of formulas and functions.
After that, it’s up to you. The book is organized more by area of focus than any-
thing else. If nance is what you do, go to Part2. If working with dates is what you
do, go to Part4. Seek, and you will nd.
1
Getting Started
with Excel
Formulas and
Functions
IN THIS PART ...
Get to know formula and function fundamentals.
Discover the dierent ways to enter functions.
Understand array-based formulas and functions.
Find out about formula errors and how to x them.
CHAPTER 1 Tapping Into Formula and Function Fundamentals 7
Chapter1
Tapping Into Formula
and Function
Fundamentals
Excel is to computer programs what a Ferrari is to cars: sleek on the outside
and a lot of power under the hood. Excel is also like a truck. It can handle all
your data— lots of it. In fact, in Excel, a single worksheet has 17,179,869,184
places to hold data. Yes, that’s what I said— more than 17 billion data placehold-
ers. And that’s on just one worksheet!
The number of available rows and columns may be fewer depending on how much
memory your computer has.
Excel is used in all types of businesses. And you know how that’s possible? By
being able to store and work with any kind of data. It doesn’t matter whether
you’re in nance or sales, whether you run an online e-commerce store or organ-
ize wilderness trips, or whether you’re charting party RSVPs or tracking the scores
of your favorite sports teams— Excel can handle all of it. Its number-crunching
ability is just awesome! And so easy to use!
IN THIS CHAPTER
»
Getting the skinny on the Excel basics
»
Writing formulas
»
Working with functions in formulas
8 PART 1 Getting Started with Excel Formulas and Functions
Just putting a bunch of information on worksheets doesn’t crunch the data or give
you sums, results, or analyses. If you want to just store your data somewhere, you
can use Excel or get a database program instead. In this book, I show you how to
build formulas and how to use the dozens of built-in functions that Excel pro-
vides. That’s where the real power of Excel is— making sense of your data.
Don’t fret that this is a challenge and that you may make mistakes. I did when I
was ramping up. Besides, Excel is very forgiving. Excel usually tells you when you
made a mistake, and sometimes it even helps you correct it. How many programs
do that? But rst, the basics. This rst chapter gives you the springboard you need
to use the rest of the book. I wish books like this were around when I was intro-
duced to computers. I had to stumble through a lot of this.
Working with Excel Fundamentals
Before you can write any formulas or crunch any numbers, you have to know where
the data goes and how to nd it again. I wouldn’t want your data to get lost! Know-
ing how worksheets store your data and present it is critical to your analysis eorts.
Understanding workbooks and worksheets
In Excel, a workbook is the same as a le. Excel opens and closes workbooks, just
as a word processor program opens and closes documents. When you start up
Excel, you are presented with a selection of templates to use, the rst one being
the standard blank workbook. Also there is a selection of recent les to select
from. After you open a new or already created workbook, click the File tab to view
basic functions such as opening, saving, printing, and closing your Excel les (not
to mention a number of other nifty functions to boot!). Figure1-1 shows the con-
tents presented on the Info tab.
The default Excel le extension is .xlsx. However you may see les with the older
.xls extension. These older les work ne in the latest version of Excel.
Start Excel and double-click the Blank Workbook icon to create a new blank work-
book. When you have more than one workbook open, you pick the one you want to
work on by clicking it on the Windows Taskbar.
A worksheet is where your data actually goes. A workbook contains at least one
worksheet. If you didn’t have at least one, where would you put the data?
Figure1-2 shows an open workbook that has two sheets, aptly named Sheet1 and
Sheet2. To the right of these worksheet tabs is the New Sheet button (looks like a
plus sign), used to add worksheets to the workbook.
CHAPTER 1 Tapping Into Formula and Function Fundamentals 9
At any given moment, one worksheet is always on top. In Figure1-2, Sheet1 is on
top. Another way of saying this is that Sheet1 is the active worksheet. There is
always one and only one active worksheet. To make another worksheet active, just
click its tab.
Worksheet, spreadsheet, and just plain old sheet are used interchangeably to mean
the worksheet.
What’s really cool is that you can change the name of the worksheets. Names like
Sheet1 and Sheet2 are just not exciting. How about Baseball Card Collection or Last
Year’s Taxes? Well, actually, Last Year’s Taxes isn’t too exciting, either.
FIGURE1-1:
The Info
tab shows
details about
your Excel le.
FIGURE1-2:
Looking at a
workbook and
worksheets.
10 PART 1 Getting Started with Excel Formulas and Functions
The point is, you can give your worksheets meaningful names. You have two ways
to do this:
»
Double-click the worksheet tab and then type a new name.
»
Right-click the worksheet tab, select Rename from the menu, and then type a
new name.
Figure1-3 shows one worksheet name already changed and another about to be
changed by right-clicking its tab.
You can try changing a worksheet name on your own. Do it the easy way:
1. Double-click a worksheet’s tab.
2. Type a new name and press Enter.
The name cannot exceed 31 characters.
You can change the color of worksheet tabs. Right-click the tab and select Tab
Color from the menu. Color coding tabs provides a great way to organize your
work.
To insert a new worksheet into a workbook, click the New Sheet button, which is
located after the last worksheet tab. Figure1-4 shows how. To delete a worksheet,
just right-click the worksheet’s tab and select Delete from the menu.
FIGURE1-3:
Changing the
name of a
worksheet.
CHAPTER 1 Tapping Into Formula and Function Fundamentals 11
Don’t delete a worksheet unless you really mean to. You cannot get it back after it
is gone. It does not go into the Windows Recycle Bin.
You can insert many new worksheets. The limit of how many is based on your
computer’s memory, but you should have no problem inserting 200 or more. Of
course, I hope you have a good reason for having so many, which brings me to the
next point.
Worksheets enable you to organize your data. Use them wisely, and you will nd
it easy to manage your data. For example, say that you are the boss (I thought
you’d like that!), and over the course of a year you track information about 30
employees. You may have 30 worksheets— one for each employee. Or you may
have 12 worksheets— one for each month. Or you may just keep it all on one
worksheet. How you use Excel is up to you, but Excel is ready to handle whatever
you throw at it.
You can set how many worksheets a new workbook has as the default. To do this,
click the File tab, click Options, and then click the General tab. Under the When
Creating New Workbooks section, use the Include This Many Sheets spinner con-
trol to select a number.
Introducing the Formulas tab
Without further ado, I present the Formulas tab of the Ribbon. The Ribbon sits at
the top of Excel. Items on the Ribbon appear as menu headers along the top of the
Excel screen, but they actually work more like tabs. Click them, and no menus
appear. Instead, the Ribbon presents the items that are related to the clicked Rib-
bon tab.
Figure 1-5 shows the top part of the screen, in which the Ribbon displays the
items that appear when you click the Formulas tab. In the gure, the Formulas tab
is set to show formula-based methods. At the left end of the tab, functions are
categorized. One of the categories is opened to show how you can access a partic-
ular function.
FIGURE1-4:
Inserting a new
worksheet.
12 PART 1 Getting Started with Excel Formulas and Functions
These groups are along the bottom of the Formulas tab:
»
Function Library: This includes the Function Wizard, the AutoSum feature,
and the categorized functions.
»
Dened Names: These features manage named areas, which are cells or
ranges on worksheets to which you assign a meaningful name for easy
reference.
»
Formula Auditing: These features are for checking and correcting formulas.
Also here is the Watch Window, which lets you keep an eye on the values in
designated cells, but within one window. In Figure1-6 you can see that a few
cells have been assigned to the Watch Window. If any values change, you can
see this in the Watch Window. Note how the watched cells are on sheets that
are not the current active sheet. Neat! By the way, you can move the Watch
Window around the screen by clicking the title area of the window and
dragging it with the mouse.
»
Calculation: This is where you manage calculation settings, such as whether
calculation is automatic or manual.
FIGURE1-5:
Getting to know
the Ribbon.
CHAPTER 1 Tapping Into Formula and Function Fundamentals 13
Another great feature that goes hand in hand with the Ribbon is the Quick Access
Toolbar. (So there is a toolbar after all!) In Figure1-5, the Quick Access Toolbar
sits just above the left side of the Ribbon. On it are icons that perform actions with
a single click. The icons are ones you select by using the Quick Access Toolbar tab
in the Excel Options dialog box. You can put the toolbar above or below the Ribbon
by clicking the Customize Quick Access Toolbar drop-down arrow on the Quick
Access Toolbar and choosing an option. In this area too are the other options for
the Quick Access Toolbar.
Working with rows, columns,
cells, ranges, and tables
A worksheet contains cells. Lots of them. Billions of them. This might seem
unmanageable, but actually it’s pretty straightforward. Figure1-7 shows a work-
sheet that contains data. Use this to look at a worksheet’s components. Each cell
can contain data or a formula. In Figure1-7, the cells contain data. Some, or even
all, cells could contain formulas, but that’s not the case here.
Columns have letter headers— A, B, C, and so on. You can see these listed hori-
zontally just above the area where the cells are. After you get past the 26th col-
umn, a double lettering system is used— AA, AB, and so on. After all the two-letter
combinations are used up, a triple-letter scheme is used. Rows are listed vertically
down the left side of the screen and use a numbering system.
You nd cells at the intersection of rows and columns. Cell A1 is the cell at the
intersection of column A and row 1. A1 is the cell’s address. There is always an
active cell— that is, a cell in which any entry would go into should you start typ-
ing. The active cell has a border around it. Also, the contents of the active cell
appear in the Formula Box.
FIGURE1-6:
Eyeing the Watch
Window.
14 PART 1 Getting Started with Excel Formulas and Functions
When I speak of, or reference, a cell, I am referring to its address. The address is
the intersection of a column and row. To talk about cell D20 means to talk about
the cell that you nd at the intersection of column D and row 20.
FIGURE1-7:
Looking at what
goes into a
worksheet.
GETTING TO KNOW THE FORMULA BAR
Taken together, the Formula Box and the Name Box make up the Formula Bar. You use
the Formula Bar quite a bit as you work with formulas and functions. The Formula Box
is used to enter and edit formulas. The Formula Box is the long entry box that starts in
the middle of the bar. When you enter a formula into this box, you can click the little
check-mark button to nish the entry. The check-mark button is visible only when you
are entering a formula. Pressing Enter also completes your entry; clicking the X cancels
the entry.
An alternative is to enter a formula directly into a cell. The Formula Box displays the for-
mula as it is being entered into the cell. When you want to see just the contents of a cell
that has a formula, make that cell active and look at its contents in the Formula Box.
Cells that have formulas do not normally display the formula, but instead display the
result of the formula. When you want to see the actual formula, the Formula Box is the
place to do it. The Name Box, on the left side of the Formula Bar, is used to select
named areas in the workbook.
CHAPTER 1 Tapping Into Formula and Function Fundamentals 15
In Figure1-7, the active cell is C7. You have a couple of ways to see this. For starters,
cell C7 has a border around it. Also notice that the column head C is shaded, as well
as row number 7. Just above the column headers are the Name Box and the Formula
Box. The Name Box is all the way to the left and shows the active cell’s address of
C7. To the right of the Name Box, the Formula Box shows the contents of cell C7.
If the Formula Bar is not visible, choose File ➪ Options, and click the Advanced tab.
Then, in the Display section in the Excel Options dialog box, select the Show For-
mula Bar check box to make the Formula Bar visible.
A range is usually a group of adjacent cells, although noncontiguous cells can be
included in the same range (but that’s mostly for rocket scientists and those
obsessed with treating data like jigsaw puzzle pieces). For your purposes, assume
a range is a group of continuous cells. Make a range right now! Here’s how:
1. Position the mouse pointer over the rst cell where you want to dene a
range.
2. Press and hold the left mouse button.
3. Move the pointer to the last cell of your desired area.
4. Release the mouse button.
Figure1-8 shows what happened when I did this. I selected a range of cells. The
address of this range is A3:D21.
FIGURE1-8:
Selecting a range
of cells.
16 PART 1 Getting Started with Excel Formulas and Functions
A range address looks like two cell addresses put together, with a colon (:) in the
middle. And that’s what it is! A range address starts with the address of the cell in
the upper left of the range, then has a colon, and ends with the address of the cell
in the lower right.
One more detail about ranges: You can give them a name. This is a great feature
because you can think about a range in terms of what it is used for, instead of what
its address is. Also, if I did not take the extra step to assign a name, the range
would be gone as soon as I clicked anywhere on the worksheet. When a range is
given a name, you can repeatedly use the range by using its name.
Say you have a list of clients on a worksheet. What’s easier— thinking of exactly
which cells are occupied, or thinking that there is your list of clients?
Throughout this book, I use areas made of cell addresses and ranges, which have
been given names. It’s time to get your feet wet creating a named area. Here’s what
you do:
1. Position the mouse pointer over a cell, click and hold the left mouse
button, and drag the pointer around.
2. Release the mouse button when you’re done.
You’ve selected an area of the worksheet.
3. Click Dene Name in the Dened Names group on the Formulas tab.
The New Name dialog box appears. Figure1-9 shows you how it looks so far.
4. Name the area or keep the suggested name. You can change the sug-
gested name as well.
Excel guesses that you want to name the area with the value it nds in the top
cell of the range. That may or may not be what you want. Change the name if
you need to. In Figure1-9, I changed the name to Clients.
FIGURE1-9:
Adding a name to
the workbook.
CHAPTER 1 Tapping Into Formula and Function Fundamentals 17
An alternative method of naming an area is to select it, type the name in the
Name Box (left of the Formula Bar), and press Enter.
5. Click OK.
That’s it. Hey, you’re already on your way to being an Excel pro! Now that you
have a named area, you can easily select your data at any time. Just go to the Name
Box and select it from the list. Figure1-10 shows how to select the Clients area.
Tables work in much the same manner as named areas. Tables have a few features
that are unavailable to simple named areas. With tables you can indicate that the
top row contains header labels. Further, tables default to have ltering ability.
Figure1-11 shows a table on a worksheet, with headings and ltering ability.
With ltering, you can limit which rows show, based on which values you select
to display.
The Tables group in the Insert tab contains the Table button for inserting a table.
FIGURE1-10:
Using the Name
Box to nd the
named area.
FIGURE1-11:
Trying a table.
18 PART 1 Getting Started with Excel Formulas and Functions
Formatting your data
Of course, you want to make your data look all spiy and shiny. Bosses like that.
Is the number 98.6 someone’s temperature? Is it a score on a test? Is it 98 dollars
and 60 cents? Is it a percentage? Any of these formats is correct:
»
98.6
»
$98.60
»
98.6%
Excel lets you format your data in just the way you need. Formatting options are
on the Home tab of the Ribbon, in the Number group.
Figure1-12 shows how formatting helps in the readability and understanding of a
worksheet. Cell B1 has a monetary amount and is formatted with the Accounting
style. Cell B2 is formatted as a percentage. The actual value in cell B2 is .05. Cell
B7 is formatted as currency. The currency format displays a negative value in
parentheses. This is just one of the formatting options for currency. Chapter 5
explains further about formatting currency data.
Besides selecting formatting on the Home tab of the Ribbon, you can use the For-
mat Cells dialog box. This is the place to go for all your formatting needs beyond
what’s available on the Home tab of the Ribbon. You can even create custom for-
mats. You can display the Format Cells dialog box two ways:
FIGURE1-12:
Formatting data.
CHAPTER 1 Tapping Into Formula and Function Fundamentals 19
»
On the Home tab, click the drop-down menu in the Number group and then
click More Number Formats.
»
Right-click any cell and select Format Cells from the pop-up menu.
Figure1-13 shows the Format Cells dialog box. I discuss this dialog box and for-
matting more extensively in Chapter5.
Getting help
Excel is complex; you can’t deny that. And lucky for all of us, help is just a key
press away. Yes, literally one key press— just press the F1 key. Try it now.
This starts the Help system. From there you can search on a keyword or browse
through the Help table of contents. Later on, when you are working with Excel
functions, you can get help on specic functions directly by clicking the Help on
This Function link in the Insert Function dialog box. Chapter2 covers the Insert
Function dialog box in detail.
FIGURE1-13:
Using the Format
Cells dialog box
for advanced
formatting
options.
20 PART 1 Getting Started with Excel Formulas and Functions
Gaining the Upper Hand on Formulas
Okay, time to get to the nitty-gritty of what Excel is all about. Sure, you can just
enter data and leave it as is, and even generate some pretty charts from it. But
getting answers from your data, or creating a summary of your data, or applying
what-if tests— all of this takes formulas.
To be specic, a formula in Excel calculates something or returns some result
based on data in one or more worksheets. These worksheets can be in more than
one workbook. A formula is placed in a cell and must start with an equal sign (=)
to tell Excel that it is a formula and not data. Sounds simple, and it is.
All formulas start with an equal (=) sign.
Look at some very basic formulas. Table1-1 shows a few formulas and tells you
what they do.
I use the word return to refer to the result of the formula or function calculation.
So saying “The formula returns a 7” is the same as saying “The formula calcu-
lated the answer to be 7.”
Entering your rst formula
Ready to enter your rst formula? Make sure Excel is running and a worksheet is
in front of you, and then follow these steps:
1. Click an empty cell.
2. Type =10+10.
3. Press Enter.
TABLE1-1 Basic Formulas
Formula What It Does
=2+2 Returns the number 4.
=A1+A2 Returns the sum of the values in cells A1 and A2, whatever those val-
ues may be. If either A1 or A2 has text in it, an error is returned.
=D5 The cell that contains this formula displays the value that is in cell D5. If
you try to enter this formula into cell D5 itself, you create a circular ref-
erence. That is a no-no. See Chapter4.
=SUM(A2:A5) Returns the sum of the values in cells A2, A3, A4, and A5.This formula
uses the SUM function to sum up all the values in the range.
CHAPTER 1 Tapping Into Formula and Function Fundamentals 21
That was easy, wasn’t it? You should see the result of the formula— the num-
ber 20.
Try another. This time you create a formula that adds the value of two cells:
1. Click any cell.
2. Type any number.
3. Click another cell.
4. Type another number.
5. Click a third cell.
This cell will contain the formula.
6. Type =.
7. Click the rst cell.
This is an important point in the creation of the formula. The formula is being
written by both your keyboard entry and your clicks of the mouse. The formula
should look about half complete, with an equal sign immediately followed by
the address of the cell you just clicked. Figure1-14 shows what this looks like.
In the example, the value 15 has been entered into cell B3 and the value 35
into cell B6. The formula was started in cell E3. Cell E3 so far has =B3 in it.
8. Type +.
9. Click the cell that has the second entered value.
In this example, this is cell B6. The formula in cell E3 now looks like this:
=B3+B6. You can see this in Figure1-15.
FIGURE1-14:
Entering a
formula that
references cells.
22 PART 1 Getting Started with Excel Formulas and Functions
10. Press Enter.
This ends the entry of the function. All done! Congratulations!
Figure1-16 shows how the example ended up. Cell E3 displays the result of the
calculation. Also notice that the Formula Bar displays the content of cell E3, which
really is the formula.
Understanding references
References abound in Excel formulas. You can reference cells. You can reference
ranges. You can reference cells and ranges on other worksheets. You can reference
cells and ranges in other workbooks. Formulas and functions are at their most
useful when you’re using references, so you need to understand them.
FIGURE1-15:
Completing the
formula.
FIGURE1-16:
A nished
formula.
CHAPTER 1 Tapping Into Formula and Function Fundamentals 23
And if that isn’t enough to stir the pot, you can use three types of cell references:
relative, absolute, and mixed. Okay, one step at a time here. Try a formula that
uses a range.
Formulas that use ranges often have a function in the formula, so use the SUM
function here:
1. Enter some numbers in many cells going down one column.
2. Click another cell where you want the result to appear.
3. Type =SUM(.
This starts the function.
4. Click the rst cell that has an entered value, hold the left mouse button
down, and drag the mouse pointer over all the cells that have values.
5. Release the mouse button.
The range address appears where the formula and function are being entered.
6. Type ).
7. Press Enter.
Give yourself a pat on the back!
Wherever you drag the mouse to enter the range address into a function, you can
also just type the address of the range, if you know what it is.
Excel is dynamic when it comes to cell addresses. If you have a cell with a formula
that references a dierent cell’s address, and you copy the formula from the rst
cell to another cell, the address of the reference inside the formula changes. Excel
updates the reference inside the formula to match the number of rows and/or
columns that separate the original cell (where the formula is being copied from)
from the new cell (where the formula is being copied to). This may be confusing,
so try an example so you can see this for yourself:
1. In cell B2, type 100.
2. In cell C2, type =B2*2.
3. Press Enter.
Cell C2 now returns the value 200.
4. If C2 is not the active cell, click it once so it becomes the active cell.
5. Press Ctrl+C, or click the Copy button in the Clipboard group on the Home
tab of the Ribbon.
24 PART 1 Getting Started with Excel Formulas and Functions
6. Click cell C3.
7. Press Ctrl+V, or click the Paste button in the Clipboard group on the
Home tab of the Ribbon.
8. If you see a strange moving line around cell C2, press the Esc key.
Cell C3 should be the active cell, but if it is not, just click it once. Look at the
Formula Bar. The contents of cell C3 are =B3*2, and not the =B2*2 that you
copied.
Did you see a moving line around a cell? That line’s called a marquee. It’s a
reminder that you are in the middle of a cut or copy operation, and the marquee
goes around the cut or copied data.
What happened? Excel, in its wisdom, assumed that if a formula in cell C2 refer-
ences the cell B2— one cell to the left— the same formula put into cell C3 is
supposed to reference cell B3— also one cell to the left.
When you’re copying formulas in Excel, relative addressing is usually what you
want. That’s why it is the default behavior. Sometimes you do not want relative
addressing, but absolute addressing. This is making a cell reference xed to an
absolute cell address so that it does not change when the formula is copied.
In an absolute cell reference, a dollar sign ($) precedes both the column letter and
the row number. You can also have a mixed reference in which the column is
absolute and the row is relative, or vice versa. To create a mixed reference, you
place the dollar sign in front of just the column letter or row number. Table1-2
has some examples.
TABLE1-2 Referencing Cells
Reference Type Formula What Happens After Copying the Formula
Relative =A1 Either, or both, the column letter A and the row
number 1 can change.
Absolute =$A$1 The column letter A and the row number 1 do
not change.
Mixed =$A1 The column letter A does not change. The row
number 1 can change.
Mixed =A$1 The column letter A can change. The row number 1
does not change.
CHAPTER 1 Tapping Into Formula and Function Fundamentals 25
Copying formulas with the ll handle
As long as I’m on the subject of copying formulas around, take a look at the ll
handle. You’re gonna love this one! The ll handle is a quick way to copy the con-
tents of a cell to other cells with just a single click and drag.
The active cell always has a little square box in the lower-right side of its border.
That is the ll handle. When you move the mouse pointer over the ll handle, the
mouse pointer changes shape to a cross. If you click and hold the mouse button, you
can drag up, down, or across over other cells. When you let go of the mouse button,
the content of the active cell automatically copies to the cells you dragged over.
A picture is worth a thousand words, so take a look at Figure1-17, which shows a
worksheet that adds some numbers. Cell E4 has this formula: =B4+C4+D4. This
formula needs to be placed in cells E5 through E15. Look closely at cell E4. The ll
handle is in the lower-right corner. I am about to use the ll handle to drag the
formula to the other cells. Clicking and holding the left mouse button down and
then dragging down to E15 does the trick.
Figure1-18 shows what the worksheet looks like after the ll handle is used to get
the formula into all the cells. This is a real time-saver. Also, you can see that the
formula in each cell of column E correctly references the cells to its left. This is the
intention of using relative referencing. For example, the formula in cell E15 ended
up with this formula: =B15+C15+D15.
FIGURE1-17:
Getting ready to
drag the formula
down.
26 PART 1 Getting Started with Excel Formulas and Functions
Assembling formulas the right way
There’s a saying in the computer business: Garbage in, garbage out. And that
applies to how formulas are put together. If a formula is constructed the wrong
way, it returns an incorrect result or an error.
Two types of errors can occur in formulas. In one type, Excel can calculate the
formula, but the result is wrong. In the other type, Excel is not able to calculate
the formula. Check out both of these.
A formula can work and still produce an incorrect result. Excel does not report an
error because there is no error for it to nd. Often, this is the result of not using
parentheses properly in the formula. Take a look at the examples in Table1-3.
All of these are valid formulas, but the placement of parentheses makes a dier-
ence in the outcome. You must take into account the order of mathematical opera-
tors when writing formulas. Here’s the order of precedence:
TABLE1-3 Order of Operations
Formula Result
=7+5*20+25/5 112
=(7+5)*20+25/5 245
=7+5*(20+25)/5 52
=(7+5*20+25)/5 26.4
FIGURE1-18:
Populating cells
with a formula by
using the ll
handle.
CHAPTER 1 Tapping Into Formula and Function Fundamentals 27
1. Parentheses
2. Exponents
3. Multiplication and division
4. Addition and subtraction
This is a key point of formulas. It is easy to just accept a returned answer. After all,
Excel is so smart. Right? Wrong! Like all computer programs, Excel can do only
what it is told. If you tell it to calculate an incorrect but structurally valid formula,
it will do so. So watch your p’s and q’s— er, your parentheses and mathematical
operators— when building formulas.
The second type of error occurs when a mistake in the formula or in the data the
formula uses prevents Excel from calculating the result. Excel makes your life
easier by telling you when such an error occurs. To be precise, it does one of the
following:
»
Excel displays a message when you attempt to enter a formula that is not
constructed correctly.
»
Excel returns an error message in the cell when there is something wrong
with the result of the calculation.
First, look at what happened when I tried to nish entering a formula that had the
wrong number of parentheses. Figure1-19 shows this.
Excel nds an uneven number of open and closed parentheses. Therefore, the
formula cannot work (it does not make sense mathematically), and Excel tells you
so. Watch for these messages; they often oer solutions.
FIGURE1-19:
Getting
a message
from Excel.
28 PART 1 Getting Started with Excel Formulas and Functions
On the other side of the fence are errors in returned values. If you got this far, the
formula’s syntax passed muster, but something went awry nonetheless. Possible
errors include
»
Attempting to perform a mathematical operation on text
»
Attempting to divide a number by 0 (a mathematical no-no)
»
Trying to reference a nonexistent cell, range, worksheet, or workbook
»
Entering the wrong type of information into an argument function
This is by no means an exhaustive list of possible error conditions, but you get the
idea. So what does Excel do about it? There are a handful of errors that Excel dis-
plays in cells with the problem formulas (see Table1-4).
Chapter4 discusses catching and handling formula errors in detail.
Using Functions in Formulas
Functions are like little utility programs that do a single thing. For example, the
SUM function sums numbers, the COUNT function counts, and the AVERAGE
function calculates an average.
There are functions to handle many needs: working with numbers, working with
text, working with dates and times, working with nance, and so on. Functions
TABLE1-4 Error Types
Error Type When It Happens
#DIV/0! You’re trying to divide by 0.
#N/A! A formula or a function inside a formula cannot nd the referenced data.
#NAME? Text in a formula is not recognized.
#NULL! A space was used instead of a comma in formulas that reference multiple
ranges. A comma is necessary to separate range references.
#NUM! A formula has numeric data that is invalid for the operation type.
#REF! A reference is invalid.
#VALUE! The wrong type of operand or function argument is used.
CHAPTER 1 Tapping Into Formula and Function Fundamentals 29
can be combined and nested (one goes inside another). Each formula returns a
value, and this value can be combined with the results of another function or for-
mula. The possibilities are nearly endless.
But functions do not exist on their own. They are always a part of a formula. Now,
that can mean that the formula is made up completely of the function or that the
formula combines the function with other functions, data, operators, or refer-
ences. But functions must follow the formula golden rule: Start with the equal sign.
Look at the examples in Table1-5.
Ready to write your rst formula with a function in it? Use the following steps to
write a function that creates an average:
1. Enter some numbers in a column’s cells.
2. Click an empty cell where you want to see the result.
3. Type =AVERAGE(.
This starts the function.
Note: Excel presents a list of functions that have the same spelling as the
function name you type. The more letters you type, the shorter the list
becomes. The advantage is, for example, typing the letters AV, using ↓ to select
the AVERAGE function, and then pressing the Tab key.
4. Click the rst cell with an entered value and, while holding the mouse
button, drag the mouse pointer over the other cells that have values.
An alternative is to enter the range of those cells.
5. Type ).
6. Press Enter.
TABLE1-5 Using Functions in Formulas
Function/Formula Result
=SUM(A1:A5) Returns the sum of the values in the range A1:A5.
This is an example of a function serving as the whole
formula.
=SUM(A1:A5)/B5 Returns the sum of the values in the range A1:A5
divided by the value in cell B5. This is an example of
mixing a function’s result with other data.
=SUM(A1:A5)+
AVERAGE(B1:B5)
Returns the sum of the range A1:A5 added with the
average of the range B1:B5. This is an example of a
formula that combines the result of two functions.
30 PART 1 Getting Started with Excel Formulas and Functions
If all went well, your worksheet should look like mine, in Figure1-20. Cell B11 has
the calculated result, but look up at the Formula Bar, and you can see the actual
function as it was entered.
Formulas and functions are dependent on the cells and ranges to which they refer.
If you change the data in one of the cells, the result returned by the function
updates. You can try this now. In the example you just did with making an aver-
age, click one of the cells with the values and enter a dierent number. The
returned average changes.
A formula can consist of nothing but a single function— preceded by an equal
sign, of course.
Looking at what goes into a function
Most functions take inputs— called arguments or parameters— that specify the
data the function is to use. Some functions take no arguments, some take one, and
others take many; it all depends on the function. The argument list is always
enclosed in parentheses following the function name. If there’s more than one
argument, the arguments are separated by commas. Look at a few examples in
Table1-6.
Some functions have required arguments and optional arguments. You must pro-
vide the required ones. The optional ones are, well, optional. But you may want to
include them if their presence helps the function return the value you need.
The IPMT function is a good example. Four arguments are required, and two more
are optional. You can read more about the IPMT function in Chapter5. You can
read more about function arguments in Chapter2.
FIGURE1-20:
Entering the
AVERAGE
function.
CHAPTER 1 Tapping Into Formula and Function Fundamentals 31
Arguing with a function
Memorizing the arguments that every function takes would be a daunting task. I
can only think that if you could pull that o, you could be on television. But back
to reality. You don’t have to memorize arguments because Excel helps you select
what function to use and then tells you which arguments are needed.
Figure1-21 shows the Insert Function dialog box. You access this great helper by
clicking the Insert Function button on the Formulas tab. The dialog box is where
you select a function to use.
TABLE1-6 Arguments in Functions
Function Comment
=NOW() Takes no arguments.
=AVERAGE(A6,A11,B7) Can take up to 255 arguments. Here, three cell ref-
erences are included as arguments. The arguments
are separated by commas.
=AVERAGE(A6:A10,A13:A19,
A23:A29)
In this example, the arguments are range refer-
ences instead of cell references. The arguments are
separated by commas.
=IPMT(B5,B6,B7,B8) Requires four arguments. Commas separate the
arguments.
FIGURE1-21:
Using the Insert
Function
dialog box.
32 PART 1 Getting Started with Excel Formulas and Functions
The dialog box contains a listing of all available functions— and there are a lot of
them! So to make matters easier, the dialog box gives you a way to search for a
function by a keyword, or you can lter the list of functions by category.
If you know which category a function belongs in, you can click the function cat-
egory button on the Formulas tab and select the function from the menu.
Try it! Here’s an example of how to use the Insert Function dialog box to multiply
a few numbers:
1. Enter three numbers in three dierent cells.
2. Click an empty cell where you want the result to appear.
3. Click the Insert Function button on the Formulas tab.
As an alternative, you can just click the little fx button on the Formula Bar. The
Insert Function dialog box appears.
4. From the category drop-down menu, select either All or Math & Trig.
5. In the list of functions, nd and select the PRODUCT function.
6. Click OK.
This closes the Insert Function dialog box and displays the Function Arguments
dialog box (see Figure1-22), where you can enter as many arguments as
needed. Initially, the dialog box may not look like it can accommodate enough
arguments. You need to enter three in this example, but it looks like there is
only room for two. This is like musical chairs!
More argument entry boxes appear as you need them. First, though, how do
you enter the argument?
FIGURE1-22:
Getting ready to
enter some
arguments to the
function.
CHAPTER 1 Tapping Into Formula and Function Fundamentals 33
7. Enter the argument in one of two ways:
•
Type the numbers or cell references in the boxes.
•
Use those funny-looking squares to the right of the entry boxes.
In Figure1-22, two entry boxes are ready to go. To the left of them are the
names Number1 and Number2. To the right of the boxes are the little squares.
These squares are actually called RefEdit controls. They make argument entry a
snap. All you do is click one, click the cell with the value, and then press Enter.
8. Click the RefEdit control to the right of the Number1 entry box.
The Function Arguments dialog box shrinks to just the size of the entry box.
9. Click the cell with the rst number.
Figure1-23 shows what the screen looks like at this point.
10. Press Enter.
The Function Arguments dialog box reappears with the argument entered in
the box. The argument is not the value in the cell, but the address of the cell
that contains the value— exactly what you want.
11. Repeat steps 7–9 to enter the other two cell references.
Figure1-24 shows what the screen should now look like.
The number of entry boxes and associated RefEdit controls grow to match the
number of needed entry boxes.
12. Click OK or press Enter to complete the function.
Figure1-25 shows the result of all this hoopla. The PRODUCT function returns the
result of the individual numbers being multiplied together.
FIGURE1-23:
Using RefEdit to
enter arguments.
34 PART 1 Getting Started with Excel Formulas and Functions
You do not have to use the Insert Function dialog box to enter functions into cells.
It is there for convenience. As you become familiar with certain functions that you
use repeatedly, you may nd it faster to just type the function directly in the cell.
Nesting functions
Nesting is something a bird does, isn’t it? Well, a bird expert would know the
answer to that one; however, I do know how to nest Excel functions. A nested func-
tion is tucked inside another function as one of its arguments. Nesting functions
FIGURE1-25:
Math was never
this easy!
FIGURE1-24:
Completing the
function entry.
CHAPTER 1 Tapping Into Formula and Function Fundamentals 35
let you return results you would have a hard time getting otherwise. (Nested func-
tions are used in examples in various places in the book. The COUNTIF, AVERAGE,
and MAX functions are discussed in Chapter9.)
Figure1-26 shows the daily closing price for the Standard & Poor’s 500 for the
month of September 2004. A possible analysis is to see how many times the clos-
ing price was higher than the average for the month. Therefore, you need to cal-
culate the average before you can compare any single price. Embed the AVERAGE
function inside another function to calculate the average rst.
When a function is nested inside another, the inner function is calculated rst.
Then that result is used as an argument for the outer function.
The COUNTIF function counts the number of cells in a range that meet a condi-
tion. The condition in this case is that any single value in the range is greater than
(>) the average of the range. The formula in cell D7 is =COUNTIF(B5:B25,">"&AVE
RAGE(B5:B25)). The AVERAGE function is evaluated rst; then the COUNTIF
function is evaluated, using the returned value from the nested function as an
argument.
FIGURE1-26:
Nesting
functions
36 PART 1 Getting Started with Excel Formulas and Functions
Nested functions are best entered directly. The Insert Function dialog box does not
make it easy to enter a nested function. Try one. In this example, you use the
AVERAGE function to nd the average of the largest values from two sets of num-
bers. The nested function in this example is MAX.You enter the MAX function
twice within the AVERAGE function. Follow these steps:
1. Enter a few dierent numbers in one column.
2. Enter a few dierent numbers in a dierent column.
3. Click an empty cell where you want the result to appear.
4. Type =AVERAGE(.
This starts the function entry.
5. Type MAX(.
6. Click the rst cell in the second set of numbers, press the mouse button,
and drag over all the cells of the rst set.
The address of this range enters into the MAX function.
7. Type ).
This ends the rst MAX function.
8. Enter a comma (,).
9. Type MAX(.
10. Click the rst cell in the second set of numbers, press the mouse button,
and drag over all the cells of the second set.
The address of this range enters into the MAX function.
11. Type ).
This ends the second MAX function.
12. Type ).
This ends the AVERAGE function.
13. Press Enter.
CHAPTER 1 Tapping Into Formula and Function Fundamentals 37
Figure 1-27 shows the result of your nested function. Cell C14 has this
formula: =AVERAGE(MAX(B4:B10),MAX(D4:D10)).
When you use nested functions, the outer function is preceded with an equal
sign (=) if it is the beginning of the formula. Any nested functions are not preceded
with an equal sign.
You can nest functions up to 64 levels.
FIGURE1-27:
Getting a result
from nested
functions.
CHAPTER 2 Saving Time with Function Tools 39
Chapter2
Saving Time with
Function Tools
Excel has so many functions that it’s both a blessing and a curse. You can do
many things with Excel functions— if you can remember them all! Even if
you remember many function names, memorizing all the arguments the
functions can use is a challenge.
Arguments are pieces of information that functions use to calculate and return a
value.
Never fear: Microsoft hasn’t left you in the dark with guring out which arguments
to use. Excel has a great utility to help you insert functions, and their arguments,
into your worksheet. This makes it a snap to nd and use the functions you need.
You can save both time and headaches, and make fewer errors to boot— so read on!
Getting Familiar with the Insert
Function Dialog Box
The Insert Function dialog box (shown in Figure2-1) is designed to simplify the
task of using functions in your worksheet. The dialog box not only helps you locate
the proper function for the task at hand but also provides information about the
IN THIS CHAPTER
»
Displaying the Insert Function
dialog box
»
Finding the function you need
»
Using the Function Arguments
dialog box
»
Entering formulas and functions
40 PART 1 Getting Started with Excel Formulas and Functions
arguments that the function takes. If you use the Insert Function dialog box, you
don’t have to type functions directly in worksheet cells. Instead, the dialog box
guides you through a (mostly) point-and-click procedure— a good thing, because
if you’re anything like me, you need all the help you can get.
In the Insert Function dialog box, you can browse functions by category or scroll
the complete alphabetical list. A search feature— you type a word or phrase in the
Search for a Function box, click the Go button, and see what comes up— is help-
ful. When you highlight a function in the Select a Function box, a brief description
of what the function does appears under the list. You can also click the Help on
This Function link at the bottom of the dialog box to view more detailed informa-
tion about the function.
You can display the Insert Function dialog box in three ways:
»
Click the Insert Function button on the Formulas tab.
»
On the Formula Bar, click the smaller Insert Function button (which looks
like fx).
»
Click the small arrow on the AutoSum button on the Formulas tab, and select
More Functions (see Figure2-2). AutoSum has a list of commonly used
functions that you can insert with a click. If you select More Functions, the
Insert Function dialog box opens.
FIGURE2-1:
Use the Insert
Function dialog
box to easily
enter functions in
a worksheet.
CHAPTER 2 Saving Time with Function Tools 41
Finding the Correct Function
The rst step in using a function is nding the one you need! Even when you do
know the one you need, you may not remember all the arguments it takes. You can
nd a function in the Insert Function dialog box in two ways:
»
Search: Type one or more keywords or a phrase in the Search for a Function
box, then click the Go button.
•
If a match is made, the Or Select a Category drop-down menu displays
Recommended, and the Select a Function box displays a list of the
functions that match your search.
•
If no match is made, the Or Select a Category drop-down menu displays
Most Recently Used functions, and the most recently used functions
appear in the Select a Function dialog box. The Search for a Function box
displays a message to rephrase the text entered for the search.
»
Browse: Click the Or Select a Category down arrow, and from the drop-down
menu, select All or an actual function category. When an actual category is
selected, the Select a Function box updates to show just the relevant func-
tions. You can look through the list to nd the function you want. Alternatively,
if you know the category, you can select it on the Formulas tab.
Table2-1 lists the categories in the Or Select a Category drop-down menu. Finding
the function you need is dierent from knowing which function you need. Excel is
great at giving you the functions, but you do need to know what to ask for.
FIGURE2-2:
The AutoSum
button oers
quick access to
basic functions
and the Insert
Function
dialog box.
42 PART 1 Getting Started with Excel Formulas and Functions
Entering Functions Using the Insert
Function Dialog Box
Now that you’ve seen how to search for or select a function, it’s time to use the
Insert Function dialog box to actually insert a function. The dialog box makes it
easy to enter functions that take no arguments and functions that do take argu-
ments. Either way, the dialog box guides you through the process of entering the
function.
TABLE2-1 Function Categories in the Insert Function Dialog Box
Category Type of Functions
Most Recently
Used
The last several functions you used.
All The entire function list, sorted alphabetically.
Financial Functions for managing loans, analyzing investments, and so on.
Date & Time Functions for calculating days of the week, elapsed time, and so on.
Math & Trig A considerable number of mathematical functions.
Statistical Functions for using descriptive and inferential statistics.
Lookup &
Reference
Functions for obtaining facts about and data on worksheets.
Database Functions for selecting data in structured rows and columns.
Text Functions for manipulating and searching text values.
Logical Boolean functions (AND, OR, and so on).
Information Functions for getting facts about worksheet cells and the data
therein.
Web A few functions that are useful when sharing data with web
services.
Engineering Engineering and some conversion functions. These functions are
also provided in the Analysis ToolPak.
Cube Functions used with online analytical processing (OLAP) cubes.
Compatibility Some functions were updated in more recent versions of Excel. The
functions in this category are the older versions that remain com-
patible with Excel 2007 and earlier versions.
User Dened Any available custom functions created in VBA code or from add-
ins. This category appears only when there are user-dened
functions.
CHAPTER 2 Saving Time with Function Tools 43
Sometimes, function arguments are not values but references to cells, ranges,
named areas, or tables. That this is also handled in the Insert Function dialog box
makes its use so benecial.
Selecting a function that takes no
arguments
Some functions return a value, period. No arguments are needed for these func-
tions. This means you don’t have to have some arguments ready to go. What could
be easier? Here’s how to enter a function that does not take any arguments. The
TODAY function is used in this example:
1. Position the cursor in the cell where you want the results to appear.
2. Click the Insert Function button on the Formulas tab to open the Insert
Function dialog box.
3. Select All in the Or Select a Category drop-down menu.
4. Scroll through the Select a Function list until you see the TODAY function,
and click it.
Figure2-3 shows what the screen looks like.
5. Click OK.
The Insert Function dialog box closes, and the Function Arguments dialog box
opens. The dialog box tells you that this function does not take any arguments.
Figure2-4 shows how the screen looks now.
FIGURE2-3:
Selecting a
function.
44 PART 1 Getting Started with Excel Formulas and Functions
6. Click OK.
Doing this closes the Function Arguments dialog box, and the function entry is
complete.
You may have noticed that the Function Arguments dialog box says that the For-
mula result will equal Volatile. This is nothing to be alarmed about! This just
means the answer can be dierent each time you use the function. For example,
TODAY will return a dierent date when used tomorrow.
Figure2-5 shows how the function’s result has been returned to the worksheet.
Cell B2 displays the date when I wrote this example. The date you see on your
screen is the current date.
Most functions do take arguments. The few that do not take arguments can return
a result without needing any information. For example, the TODAY function just
returns the current date. It doesn’t need any information to gure this out.
Selecting a function that uses arguments
Most functions take arguments to provide the information that the functions need
to perform their calculations. Some functions use a single argument; others use
many. Taking arguments and using arguments are interchangeable terms. Most
FIGURE2-4:
Conrming that
no arguments
exist with the
Function
Arguments
dialog box.
FIGURE2-5:
Populating a
worksheet cell
with today’s date.
CHAPTER 2 Saving Time with Function Tools 45
functions take arguments, but the number of arguments depends on the actual
function. Some functions take a single argument, and some can take up to 255.
The following example shows how to use the Insert Function dialog box to enter a
function that does use arguments. The example uses the PRODUCT function.
Here’s how to enter the function and its arguments:
1. Position the cursor in the cell where you want the results to appear.
2. Click the Insert Function button on the Formulas tab.
Doing this opens the Insert Function dialog box.
3. Select Math & Trig in the Or Select a Category drop-down menu.
4. Scroll through the Select a Function list until you see the PRODUCT
function and then click it.
Figure2-6 shows what the screen looks like.
5. Click OK.
The Insert Function dialog box closes, and the Function Arguments dialog box
opens. Figure2-7 shows what the screen looks like. The dialog box tells you
that this function can take up to 255 arguments, yet there appears to be room
for only 2. As you enter arguments, the dialog box provides a scroll bar to
manage multiple arguments.
6. In the Function Arguments dialog box, enter a number in the
Number1 box.
FIGURE2-6:
Preparing to
multiply some
numbers with the
PRODUCT
function.
46 PART 1 Getting Started with Excel Formulas and Functions
7. Enter another number in the Number2 box.
You are entering actual arguments. As you enter numbers in the dialog box, a
scroll bar appears, letting you add more arguments. Enter as many as you like,
up to 255. Figure2-8 shows how I entered eight arguments. Also look at the
bottom left of the dialog box. As you enter functions, the formula result is
instantly calculated. Wouldn’t it be nice to be that smart?
8. Click OK to complete the function entry.
Figure2-9 shows the worksheet’s result.
FIGURE2-7:
Ready to input
function
arguments.
FIGURE2-8:
Getting instant
results in the
Function
Arguments
dialog box.
CHAPTER 2 Saving Time with Function Tools 47
Entering cells, ranges, named areas,
and tables as function arguments
Excel is so cool. You not only can provide single cell references as arguments, but
also, in many cases you can enter an entire range reference, or the name of an area
or table, as a single argument! What’s more, you can enter these arguments by
using either the keyboard or the mouse.
This example demonstrates using both single cell and range references as well as a
named area and table as arguments. For this example, I use the SUM function. Here’s
how to use the Insert Function dialog box to enter the function and its arguments:
1. Enter some numbers in a worksheet in contiguous cells.
2. Select the cells and then click the Table button on the Insert tab.
The Create Table dialog box opens.
3. Click OK to complete making the table.
The Ribbon should display table styles and other options. (If not, look along the
Excel title bar for Table Design, and click it.) On the left end of the Ribbon is the
name that Excel gave the table. You can change the name of the table, as well
as the appearance. Jot down the name of the table. You need to re-enter the
table name further in these steps.
4. Somewhere else on the worksheet, enter numbers in contiguous cells.
5. Select the cells and then click the Dene Name button on the
Formulas tab.
The New Name dialog box opens.
6. Enter a name for the area.
I used the name MyArea. Figure2-10 shows how the worksheet is shaping up.
7. Enter some more numbers in contiguous cells, either across a row or
down a column.
8. Enter a single number in cell A1.
9. Click an empty cell where you want the result to appear.
FIGURE2-9:
Getting the nal
answer from the
function.
48 PART 1 Getting Started with Excel Formulas and Functions
10. Click the Insert Function button on the Formulas tab.
The Insert Function dialog box opens.
11. Select the SUM function.
SUM is in the All or Math & Trig category, and possibly in the Recently Used
category.
12. Click OK.
The Function Arguments dialog box opens.
To the right of each Number box is a small fancy button— a special Excel
control sometimes called the RefEdit. It allows you to leave the dialog box,
select a cell or range on the worksheet, and then go back to the dialog box.
Whatever cell or range you click or drag over on the worksheet is brought into
the entry box as a reference.
You can type cell and range references, named areas, and table names directly
in the Number boxes as well. You can also click directly on cells or ranges on
the worksheet. The RefEdit controls are there to use if you want to work with
the mouse instead.
13. Click the rst RefEdit.
The dialog box shrinks so that the only control visible is the eld where you
enter data. Click cell A1, where you entered a number.
14. Press Enter.
The Function Arguments dialog box reappears.
15. In the second entry box, type the name of your named area.
If you don’t remember the name you used, use the RefEdit control to select the
area on the worksheet.
FIGURE2-10:
Adding a table
and a named
area to a
worksheet.
CHAPTER 2 Saving Time with Function Tools 49
16. In the third entry box, enter your table name and press Enter.
17. If you don’t remember the name you used, use the RefEdit control to
select the table.
18. In the fourth entry box, enter a range from the worksheet where some
values are located and press Enter.
It does not matter if this range is part of a named area or table. Use the RefEdit
control if you want to just drag the mouse over a range of numbers. Your
screen should look similar to Figure2-11.
19. Click OK.
The nal sum from the various parts of the worksheet displays in the cell
where the function was entered. Figure2-12 shows how the example work-
sheet turned out.
Congratulations! You did it. You successfully inserted a function that took a cell
reference, a range reference, a named area, and a table name. You’re harnessing
the power of Excel. Look at the result— the sum of many numbers located in var-
ious parts of the worksheet. Just imagine how much summing you can do. You can
have up to 255 inputs, and if necessary, each one can be a range of cells.
You can use the Insert Function dialog box at any time while entering a formula.
This is helpful when the formula uses some values and references in addition to a
function. Just open the Insert Function dialog box when the formula entry is at the
point where the function goes.
FIGURE2-11:
Entering
arguments.
50 PART 1 Getting Started with Excel Formulas and Functions
Getting help in the Insert
Function dialog box
The number of functions and their exhaustive capabilities give you the power to
do great things in Excel. However, from time to time, you may need guidance on
how to get functions to work. Luckily for you, help is just a click away.
Both the Insert Function and Function Arguments dialog boxes have a link to
the Help system. At any time, you can click the Help on This Function link in the
lower-left corner of the dialog box and get help on the function you’re using. The
Help system has many examples. Often, reviewing how a function works leads you
to other, similar functions that may be better suited to your situation.
Using the Function Arguments
dialog box to edit functions
Excel makes entering functions with the Insert Function dialog box easy. But what
do you do when you need to change a function that has already been entered in a
cell? What about adding arguments or taking some away? There is an easy way to
do this! Follow these steps:
1. Click the cell with the existing function.
2. Click the Insert Function button.
The Function Argument dialog box appears. This dialog box is already set to
work with your function. In fact, the arguments that have already been entered
in the function are displayed in the dialog box as well!
FIGURE2-12:
Calculating a sum
based on cell and
range references.
CHAPTER 2 Saving Time with Function Tools 51
3. Add, edit, or delete arguments, as follows:
•
To add an argument (if the function allows), use the RefEdit control to pick
up the extra values from the worksheet. Alternatively, if you click the
bottom argument reference, a new box opens below it, and you can enter
a value or range in that box.
•
To edit an argument, simply click it and change it.
•
To delete an argument, click it and press the Backspace key.
4. Click OK when you’re nished.
The function is updated with your changes.
Directly Entering Formulas and Functions
As you get sharp with functions, you will likely bypass the Insert Function dialog
box altogether and enter functions directly. One place you can do this is in the
Formula Bar. Another way is to just type in a cell.
Entering formulas and functions
in the Formula Bar
When you place your entry in the Formula Bar, the entry is really going into the
active cell. However, because the active cell can be anywhere, you may prefer
entering formulas and functions directly in the Formula Bar. That way, you know
that the entry will land where you need it. Before you enter a formula in the For-
mula Box (on the right end of the Formula Bar), the Name Box on the left lets you
know where the entry will end up. The cell receiving the entry may be not be in the
visible area of the worksheet. Gosh, it could be a million rows down and thousands
of columns to the right! After you start entering the formula, the Name Box
becomes a drop-down menu of functions. This menu is useful for nesting func-
tions. As you enter a function in the Formula Box, you can click a function in the
Name Box, and the function is inserted into the entry you started in the Formula
Box. Confused? Imagine what I went through explaining that! Seriously, though,
this is a helpful way to assemble nested functions. Try it, and get used to it; it will
add to your Excel smarts.
When your entry is nished, press Enter or click the little check-mark Enter but-
ton to the left of the Formula Box.
52 PART 1 Getting Started with Excel Formulas and Functions
Figure2-13 makes this clear. A formula is being entered in the Formula Box, and
the Name Box follows along with the function(s) being entered. Note, though, that
the active cell is not in the viewable area of the worksheet. It must be below and/
or to the right of the viewable area because the top-left portion of the worksheet
is shown in Figure2-13.
In between the Name Box and the Formula Box are three small buttons. From left
to right, they do the following:
»
Cancel the entry.
»
Complete the entry.
»
Display the Insert Function dialog box.
The Cancel and Enter Function buttons are enabled only when you enter a for-
mula, a function, or just plain old values on the Formula Bar or directly in a cell.
Entering formulas and functions
directly in worksheet cells
Perhaps the easiest entry method is typing the formula directly in a cell. Just type
formulas that contain no functions and press Enter to complete the entry. Try this
simple example:
1. Click a cell where the formula is to be entered.
2. Enter this simple math-based formula:
=6+(9/5)*100
3. Press Enter.
The answer is 186. (Don’t forget the order of operators; see Chapter18 for
more information about the order of mathematical operators.)
Excel makes entering functions in your formulas as easy as a click. As you type the
rst letter of a function in a cell, a list of functions starting with that letter is
listed immediately (see Figure2-14).
FIGURE2-13:
Entering a
formula in the
Formula Box has
its conveniences.
CHAPTER 2 Saving Time with Function Tools 53
The desired function in this example is MIN, which returns the minimum value
from a group of values. As soon as you type M (rst enter the equal sign if this is
the start of a formula entry), the list in Figure2-14 appears, showing all the func-
tions beginning with M. Now that an option exists, either keep typing the full
function name, or scroll to MIN and press the Tab key. Figure2-15 shows just
what happens when you do the latter. MIN is completed and provides the required
syntax structure— not much thinking involved! Now your brain can concentrate
on more interesting things, such as poker odds. (Will Microsoft ever create a func-
tion category for calculating poker odds? Please?) In Figure2-15, the MIN func-
tion is used to nd the minimum value in the range A7:A15 (which is multiplied
with the sum of the values in A1 plus A2). Entering the closing parenthesis and
then pressing Enter completes the function. In this example, the answer is 1222.
FIGURE2-14:
Entering
functions
has never been
this easy.
FIGURE2-15:
Completing the
direct-in-the-cell
formula entry.
54 PART 1 Getting Started with Excel Formulas and Functions
The formula in D5 is =(A1+A2)*MIN(A7:A15).
Excel’s capability to show a list of functions based on spelling is called Formula
AutoComplete.
You can turn Formula AutoComplete on or o in the Excel Options dialog box by
following these steps:
1. Click the File tab at the top left of the screen.
2. Click Options.
3. In the Excel Options dialog box, select the Formulas tab.
4. In the Working with Formulas section, select or deselect the Formula
AutoComplete check box (see Figure2-16).
5. Click OK.
FIGURE2-16:
Setting Formula
AutoComplete.
CHAPTER 3 Saying “Array!” for Formulas and Functions 55
Chapter3
Saying “Array!” for
Formulas and Functions
Excel is really quite sophisticated; its many built-in functions make your work
easier. On top of that, Excel allows you to tell functions to work on entire sets
of values, called arrays, which makes for even more clever analysis.
An array is a set of two or more values (for example, the contents of two or more
worksheet cells, or even the contents of two or more worksheet ranges). Certain
functions use arrays for arguments.
You may be thinking, “Hey, how is this dierent from just entering a bunch of
arguments?” You’re right in the comparison. For example, the SUM function can
take up to 255 arguments. Isn’t this the same as giving the function an array with
255 values? Well, yes and no. It’s the same idea, but using the array approach can
streamline your work, as you soon see.
There is even another side to array functions. Some of the functions return an
array. Yes, that’s right. Most of the time a function returns a single value into a
single cell. In this chapter, I show you how a function returns a group of values
into multiple cells.
IN THIS CHAPTER
»
Understanding arrays
»
Creating formulas that use arrays
»
Using functions that return arrays
of data
56 PART 1 Getting Started with Excel Formulas and Functions
Discovering Arrays
An array is like a box. It can hold a number of items. In Excel, an array holds a
collection of values or cell references. These arrays are used exclusively in formu-
las and functions. That is, the association of some values as one cohesive group
exists just for the purpose of calculating results. An array diers from the named
areas (a range of cells) that you can create in Excel. Named areas become part of
the worksheet and can be referenced at any time.
Named areas are set using the New Name dialog box, as shown in Figure3-1. By
contrast, there is no such dialog box or method to create arrays that can be refer-
enced from functions or formulas. Arrays, instead, are embedded in formulas.
Named areas are easily referenced in formulas. For example, if a workbook con-
tains a named area Sales, the values of all the cells in Sales can be summed up like
this:
=SUM(Sales)
Assume that Sales contains three cells with these values: 10, 15, and 20. These
values, of course, can be entered directly in the SUM function like this:
=SUM(10,15,20)
This is almost an array, but not quite. Excel recognizes a group of values to be an
array when they are enclosed in braces— { and }. Therefore, to enter the array of
values into the function, you make an entry that looks like this:
=SUM({10,15,20})
Essentially the braces tell Excel to treat the group of values as an array. So far, you
may be wondering about the usefulness of an array, but in the next section, I show
FIGURE3-1:
Creating a named
area with the
New Name
dialog box.
CHAPTER 3 Saying “Array!” for Formulas and Functions 57
you how using arrays with standard functions such as SUM can provide sophisti-
cated results.
To enter values as an array within a function, enclose them in braces. Braces have
a curly look and are not to be confused with brackets. On a typical keyboard, braces
and brackets are on the same key. Holding the Shift key while pressing the brace/
bracket key provides the brace.
However, getting the braces into the formula takes a particular keystroke. You
don’t type braces directly.
Using Arrays in Formulas
You can use arrays when entering formulas and functions. Typically, the argu-
ments to a function are entered in a dierent manner, which I demonstrate in this
section. Using arrays can save entry steps and deliver an answer in a single for-
mula. This is useful in situations that normally require a set of intermediate cal-
culations from which the nal result is calculated. I don’t know about you, but I
like shortcuts, especially when I have too much to do!
Here’s an example: The SUM function is normally used to add a few numbers
together. Summing up a few numbers doesn’t require an array formula per se, but
what about summing up the results of other calculations? This next example
shows how using an array simplies getting to the nal result.
Figure3-2 shows a small portfolio of stocks. Column A has the stock symbols,
column B has the number of shares per stock, and column C has a recent price for
each stock.
FIGURE3-2:
A stock portfolio.
58 PART 1 Getting Started with Excel Formulas and Functions
The task is to nd out the total value of the portfolio. The typical way to do this
is to
1. Multiply the number of shares for each stock by its price.
2. Sum up the results from Step 1.
Figure3-3 shows a common way to do this. Column D contains formulas to calcu-
late the value of each stock in the portfolio. This is done by multiplying the num-
ber of shares for each stock by its price. For example, cell D4 contains the formula
=B4*C4. Cell D10 sums up the interim results with the formula =SUM(D4:D8).
The method shown in Figure3-3 requires creating additional calculations— those
in column D.These calculations are necessary if you need to know the value of
each stock, but not if all you need to know is the value of the portfolio as a whole.
Fortunately, alternatives to this standard approach exist. One is to embed the sep-
arate multiplicative steps directly in the SUM function, like this:
=SUM(B4*C4,B5*C5,B6*C6,B7*C7,B8*C8)
That works, but it’s bloated, to say the least. What if you had 20 stocks in the port-
folio? Forget it!
Another alternative is the SUMPRODUCT function. This function sums the prod-
ucts, just as the other methods shown here do. The limitation, however, is that
SUMPRODUCT can be used only for summing. It cannot, for example, give you an
average.
In many situations such as this one, your best bet is to use an array function.
Figure3-4 shows the correct result from using the SUM function entered as an array
function. Notice that the formula in the Formula Bar begins and ends with a brace.
FIGURE3-3:
Calculating
the value of
a stock portfolio
the old-
fashioned way.
CHAPTER 3 Saying “Array!” for Formulas and Functions 59
The syntax is important. Two ranges are entered in the function: One contains the
cells that hold the number of shares, and the other contains the cells that have the
stock prices. These are multiplied in the function by entering the multiplication
operator (*):
{=SUM(B4:B8*C4:C8)}
Ctrl+Shift+Enter had been pressed to turn the whole thing into an array function.
You use that special keystroke combination when you nish the formula, not
before. Note the lack of subtotals (per stock) in cells D4:D8. Compare Figure3-4
to Figure3-3, and you can see the dierence.
Use Ctrl+Shift+Enter to turn a formula into an array formula. You must use the key
combination after entering the formula instead of pressing Enter. The key combi-
nation takes the place of pressing Enter.
Here’s how you use an array with the SUM function:
1. Enter two columns of values.
The two lists must be the same size.
2. Position the cursor in the cell where you want the result to appear.
3. Type =SUM( to start the function.
Note that a brace is not entered in this step.
4. Click the rst cell in the rst list, hold the left mouse button down, drag
the pointer over the rst list, and then release the mouse button.
5. Type the multiplication sign (*).
6. Click the rst cell of the second list, hold down the left mouse button,
and drag the pointer over the second list.
7. Release the mouse button.
FIGURE3-4:
Calculating the
value of a stock
portfolio using an
array function.
60 PART 1 Getting Started with Excel Formulas and Functions
8. Type ).
9. Press Ctrl+Shift+Enter to end the function.
Do not just press Enter by itself when using an array with the SUM function.
Array functions are useful for saving steps in mathematical operations. Therefore,
you can apply these examples to a number of functions, such as AVERAGE, MAX,
MIN, and so on.
As another example, suppose that you run a eet of taxis, and you need to calcu-
late the average cost of gasoline per mile driven. This is easy to calculate for a
single vehicle. You just divide the total spent on gasoline by the total miles driven
for a given period of time. The calculation looks like this:
cost of gasoline per mile = total spent on gasoline ÷ total miles driven
How can you easily calculate this for a eet of vehicles? Figure3-5 shows how this
is done. The vehicles are listed in column A, the total miles driven for the month
appear in column B, and the total amounts spent on gasoline appear in column C.
One single formula in cell C21 answers the question. When you use the AVERAGE
function in an array formula, the result is returned without the need for any inter-
mediate calculations. The formula looks like this:
{=AVERAGE(C6:C17/B6:B17)}
FIGURE3-5:
Making an easy
calculation using
an array formula.
CHAPTER 3 Saying “Array!” for Formulas and Functions 61
Working with Functions
That Return Arrays
A few functions actually return arrays of data. Instead of providing a single result,
as most functions do, these functions return several values. The number of actual
returned values is directly related to the function’s arguments. The returned val-
ues go into a range of cells.
Excel array functions accept arrays as arguments and possibly return arrays of
data.
A good example of this is the TRANSPOSE function. This interesting function is
used to reorient data. Data situated a given way in columns and rows is transposed
(changed to be presented instead in rows and columns). Figure3-6 shows how
this works.
Cells B3 through D10 contain information about departments in a company.
Departments are listed going down column B.Note that the area of B3 through D10
specically occupies three columns and eight rows. The header row is included in
the area.
Cells B16 through I18 contain the transposed data. It is the same data, but now it
occupies eight columns and three rows. In total number of cells, this is the same
size as the original area. Just as important is that the area is made up of the same
dimensions, just reversed. That is, a 3-by-8 area became an 8-by-3 area.
FIGURE3-6:
Transposing data.
62 PART 1 Getting Started with Excel Formulas and Functions
The number of cells remains 24. However, the transposed area has not been
altered to be 6 by 4, 2 by 12, or any other two dimensions that cover 24 cells.
Every single cell in the B16:I18 range contains the same formula:
{=TRANSPOSE(B3:D10)}. However, the function was entered only once.
In detail, here is how you can use the TRANSPOSE function:
1. Enter some data that occupies at least two adjacent cells.
Creating an area of data that spans multiple rows and columns is best for
seeing how useful the function is.
2. Elsewhere on the worksheet, select an area that covers the same number
of cells but has the length of the sides of the original area reversed.
For example:
•
If the original area is 2 columns and 6 rows, select an area that is 6
columns and 2 rows.
•
If the original area is 1 column and 2 rows, select an area that is 2 columns
and 1 row.
•
If the original area is 200 columns and 201 rows, select an area that is 201
columns and 200 rows.
•
If the original area is 5 columns and 5 rows, select an area that is 5
columns and 5 rows. (A square area is transposed into a square area.)
Figure3-7 shows an area of data and a selected area ready to receive the
transposed data. The original data area occupies 11 columns and 3 rows. The
selected area is 3 columns by 11 rows.
FIGURE3-7:
Preparing an area
to receive
transposed data.
CHAPTER 3 Saying “Array!” for Formulas and Functions 63
3. Type =TRANSPOSE( to start the function.
Because the receiving area is already selected, the entry goes into the rst cell
of the area.
4. Click the rst cell in the original data, drag the pointer over the entire
original data area while keeping the mouse button down, and release the
mouse button when the area is selected.
The function now shows the range of the original area. Figure3-8 shows how
the entry should appear at this step.
5. Type ).
6. Press Ctrl+Shift+Enter to end the function.
Note that the transposed data does not necessarily take on the formatting of the
original area. You may need to format the area. Figure3-9 shows the result of
using TRANSPOSE and then formatting the transposed data.
Wait! Isn’t this a waste of time? Excel can easily transpose data when you use the
Paste Special dialog box. Simply copying a range of data and using this dialog box
to paste the data gives the same result as the TRANSPOSE function. Or does it?
Figure 3-10 shows the Paste Special dialog box with the Transpose check box
selected. This option transposes the data. You don’t even have to select the correct
number of rows and columns where the transposed data will land. It just appears
transposed, with the active cell as the corner of the area.
FIGURE3-8:
Completing the
function.
64 PART 1 Getting Started with Excel Formulas and Functions
However, when data is transposed with the Paste Special dialog box, the actual
data is copied to the new area. By contrast, the TRANSPOSE function pastes a for-
mula that references the original data— and that is the key point. When data is
changed in the original area, the change is reected in the new, transposed area if
the TRANSPOSE function was used.
You can transpose data in two ways. The area lled with the TRANSPOSE function
references the original data and will update as original data is changed. Using the
Paste Special dialog box to transpose data creates values that do not update when
the original data changes.
FIGURE3-10:
Using the Paste
Special dialog box
to transpose
data.
FIGURE3-9:
Transposed data
after formatting.
CHAPTER 4 Fixing Formula Boo-Boos 65
Chapter4
Fixing Formula Boo-Boos
Excel would be nothing if it didn’t enable you to create formulas. Creating
formulas is, after all, the real purpose of a worksheet: to allow you to build a
solution that pertains to your specic needs. Without formulas, Excel would
be no more than a place to store information. Boring!
Excel allows formulas to have up to 8,192 characters. This means you can create
some monster formulas! Formulas can reference cells that have formulas that
reference other cells that have formulas that reference...well, you get the idea!
Ah, but this comes at a price. How can you track down errors in long formulas?
How can you avoid them in the rst place? In this chapter, I explain how Excel
steers you away from entering problematic formulas, and discuss how to correct
completed formulas that are not working the way you intended.
Catching Errors As You Enter Them
Excel is keeping an eye on you when you enter formulas. Don’t be worried! This is
a good thing. You aren’t being graded. Excel is helping you, not testing you.
IN THIS CHAPTER
»
Preventing errors with Excel
»
Following the ow of cell and range
references to and from formulas
»
Keeping an eye on changes with the
Watch Window
»
Stepping through a calculation to nd
the error
»
Displaying user-friendly error
messages
66 PART 1 Getting Started with Excel Formulas and Functions
All formulas start with an equal sign. When you complete an entry by pressing
Enter or Tab (or clicking another cell), Excel scans the entry. If the entry did
indeed start with an equal sign, Excel immediately looks for three major problems:
»
Do the numbers of open and closed parentheses match?
»
Does the formula reference the same cell it is entered in? Suppose that cell A1
has this formula: =A1*5. This is called a circular reference. It’s a bit like a dog
chasing his tail.
»
Does the formula refer to a nonexistent reference?
Each of the problems is handled dierently. Excel oers a x for mismatched
parentheses but only warns you about formulas that reference the cell they are
entered in. For nonexistent references, Excel asks you where to nd them. Excel
displays an Open File dialog box that you use to browse to the reference, assuming
that the reference is meant to come from an external workbook. If a reference to
an external workbook was not the intention, the dialog box won’t make sense. In
this case, dismiss the dialog box and edit the formula.
Getting parentheses to match
In a mathematical formula, each open parenthesis must have a matching closed
parenthesis. Excel checks your formulas to make sure they comply. Figure 4-1
shows a simple business calculation that requires parentheses to make sense. The
result is based on multiplying units by price per unit, adding an additional pur-
chase amount to that, applying a discount, and nally applying tax.
FIGURE4-1:
Using
parentheses
in a formula.
CHAPTER 4 Fixing Formula Boo-Boos 67
In math terms, here is how the formula works:
(units sold × price per unit + additional purchases) × discount × (1 + tax rate)
The placement of the parentheses is critical to making the formula work. Excel
won’t sense a problem if any particular parenthesis is in the wrong place as long
as there are matching numbers of open and closed parentheses. For example,
using the cells and values from Figure4-1, Table4-1 shows some possibilities of
valid formulas that return incorrect answers.
Correct parentheses placement and a rm understanding of mathematical-
operator precedence are critical to calculating correct answers. I suggest a brush-
up on these basic math concepts if you aren’t sure how to construct your formulas
(see Chapter18).
There is a great mnemonic for orders of operation: Please excuse my dear Aunt
Sally. That is meant to help you remember parentheses, exponents, multiplica-
tion, division, addition, and subtraction (PEMDAS). By the way, I had to excuse my
dear Aunt Honey for undercooking the stung one year at Thanksgiving. Great
meal, and then we all got sick!
What if, during entry, a parenthesis is left out? When you try to complete the
entry, Excel pops up a warning and a suggestion. In this example, the rst closed
parenthesis is purposely left out. Here is the incorrect formula: =(B3*B4+B6*
B8*(1+B9).
Figure4-2 shows how Excel catches the error and oers a solution.
Don’t be hasty! The correction proposed by Excel corrects the mismatched paren-
theses but does not create the correct formula. Look closely at the following exam-
ple of a proposed correction by Excel: =(B3*B4+B6*B8*(1+B9)).
TABLE4-1 Valid Formulas That Return Incorrect Answers
Formula Result
=B3*(B4+B6)*B8*(1+B9) 5626.84
=B3*B4+(B6*B8)*(1+B9) 549.13
=(B3*B4+B6*B8)*(1+B9) 589.96
=(B3*B4+B6)*(B8*1+B9) 299.15
68 PART 1 Getting Started with Excel Formulas and Functions
But what you really need is this: =(B3*B4+B6)*B8*(1+B9).
Excel simply added the missing parenthesis to the end of the formula. A good idea,
but not good enough. If the proposed correction were accepted, a result of $549.13
would be returned in this example. The correct answer is $268.46. In this case,
you should reject the proposal and x the formula yourself.
Do not assume Excel’s proposed formula corrections are right for you. Carefully
review the proposed correction, and accept or reject it accordingly.
Avoiding circular references
A circular reference occurs when a cell refers to itself, whether directly or indirectly.
For example, if =100+A2 is entered in cell A2, a direct circular reference has been
created. An indirect circular reference is when the formula in a given cell refers to
one or more other cells that in return refer to the original cell. For example, a
formula in A1 refers to cell A2, A2 refers to A3, and A3 refers back to A1.
Figure 4-3 shows a worksheet that has a direct circular reference. Cell D10 is
meant to sum the values above it but mistakenly includes itself in the sum:
=SUM(D4:D10). Excel reports the problem in the message box shown in
Figure4-3.
If Automatic Calculation is turned o, the circular reference is unnoticed until you
do a manual calc (by pressing F9) or change the setting to Automatic Calculation.
FIGURE4-2:
Fixing
mismatched
parentheses.
CHAPTER 4 Fixing Formula Boo-Boos 69
When the dialog box in Figure4-3 appears, you have two choices:
»
Clicking OK lets the formula entry complete, but the result is not correct. In
fact, you may just end up with a zero.
»
Clicking Help takes you to Excel Help’s Circular Reference topic.
Figure4-4 shows the Formulas tab of the Excel Options dialog box. Here is where
calculation— automatic or manual— is set. Note that the Enable Iterative Calcu-
lation check box is here as well. When this option is checked, circular references
are allowed. How they calculate values in this case is dependent on the Maximum
Iterations and Maximum Change settings.
FIGURE4-3:
Correcting a
circular
reference.
FIGURE4-4:
Setting
calculation and
iteration options.
70 PART 1 Getting Started with Excel Formulas and Functions
Checking and applying iterations on the Calculation tab of the Excel Options dia-
log box enables you to use circular references in your formulas. These references
are useful for certain advanced calculations that are beyond the scope of this book
(see Excel Help for more information).
Excel has an approach to hunting down circular references. The Formulas tab on
the Ribbon has a group named Formula Auditing. In this group is an Error Check-
ing drop-down menu that shows any circular references (see Figure4-5).
The drop-down menu lists circular references, and clicking one takes you to the
listed cell with the circular reference. This enables you to get to circular references
easily instead of having to review all your formulas. Hey, that’s a timesaver!
You may notice that the circular reference error message appears only the rst
time you enter a circular reference formula. Excel’s behavior after that is to place
a zero in the cell with the problematic formula. However, you are still notied of
the issue by viewing the status bar or by seeing it in the Error Checking drop-
down menu, as shown in Figure4-5.
Mending broken links
Formulas can reference external workbooks. As an example, a formula could be
written like this: ='C:\Inventory\[Inventory.xlsx]Engine Parts'!$D$8. The
formula uses the value in the external workbook Inventory.xlsx. What if the
workbook is not found?
When a formula references an unfound workbook, a dialog box opens to let you
navigate to an appropriate workbook elsewhere. Figure4-6 shows that the dialog
box has opened after the Inventory.xslx le is referenced. This le could not be
found, and Excel is prompting you to nd it.
FIGURE4-5:
Hunting down
circular
references.
CHAPTER 4 Fixing Formula Boo-Boos 71
The Edit Links dialog box gives you other options for handling broken links. Click
the Data tab on the Ribbon, and click Edit Links in the Queries & Connections
group. Doing this opens the Edit Links dialog box, as shown in Figure4-7.
The buttons along the right side of the dialog box work like this:
»
Update Values: When external workbooks are where they should be, this
action gets the values from the external workbooks, and the cells with those
formulas are recalculated. When there are broken links, an Open File dialog
box appears, letting you browse to a le from which to get the values. This le
does not necessarily have to be the missing workbook; it could be another
workbook. Be aware that using Update Values in this manner does not x the
link. It helps you get values but does not change the way formulas are written.
Instead, use the Change Source option, listed next.
FIGURE4-6:
Browsing for an
unfound external
workbook.
FIGURE4-7:
Using the Edit
Links dialog box
to correct
external
reference
problems.
72 PART 1 Getting Started with Excel Formulas and Functions
»
Change Source: This option displays an Open File dialog box that lets you
select an external workbook to use. Selecting a workbook in this dialog box
actually alters the formula that references the external workbook. So this is
the best course to take to permanently x a broken link.
»
Open Source: In the case of broken links, this action does nothing because
the source (the external workbook) cannot be found. An error message
conrms this. In the case of working links, this action opens the workbook
referenced in the link.
»
Break Link: This action converts formulas that contain external links to the
calculated values. In other words, the cells that contain formulas with external
links are replaced with a value; the formulas are removed. Make sure this is what
you want to do. You cannot undo this action, and it can be a serious mistake if
you do it unintentionally. Excel displays a warning dialog box, as shown in
Figure4-8.
»
Check Status: This action provides the status of links. A number of values are
possible (OK, Unknown, Error: Source not found, Error: Worksheet not found,
and so on). In the Edit Links dialog box (refer to Figure4-7), Status is a column
in the middle of the dialog box. Each link receives its own status.
The Edit Links dialog box, shown in Figure4-7, also has a Startup Prompt button
in the bottom-left corner. Clicking this button lets you choose what the workbook
should do when it’s opened and there are missing external links. The choices are
»
Let users choose whether to display the alert.
»
Don’t display the alert, and don’t update automatic links.
»
Don’t display the alert, and update links.
Using the Formula Error Checker
Some errors are immediately apparent, such as mismatched parentheses explained
earlier. Other types of entries are not blatant errors, but resemble errors. In this
case, Excel alerts you to the possible problem and lets you choose how to handle it.
Figure4-9 shows a few numbers and a sum at the bottom. The formula in cell B10
is =SUM(B4:B9). There is nothing wrong here— no possible error yet.
FIGURE4-8:
Conrming that
you mean to
break links.
CHAPTER 4 Fixing Formula Boo-Boos 73
Note that in Figure4-9, the headings row is not adjacent to the rows of informa-
tion. Rows 2 and 3 are between the headings and the data. This is not unusual,
because it leads to a clean-looking report.
However, watch what happens if a value is accidentally entered in the area between
the headings and the data. The formula in cell B10 calculates values starting in
row 4. When a value is entered in cell B3, Excel alerts you that there may be an
error. You can see this in Figure4-10. A small triangle is now visible in the upper-
left corner of cell B10— the cell with the formula.
Clicking cell B10 and moving the pointer over the triangle causes a small symbol
with an exclamation point to appear. Clicking the symbol displays a list of choices,
as shown in Figure4-11.
FIGURE4-9:
Calculating a sum
with no possible
error.
FIGURE4-10:
Excel detects a
possible error.
74 PART 1 Getting Started with Excel Formulas and Functions
An error is represented by a triangle in the upper-left corner of a cell. This is dif-
ferent from a smart tag, which appears as a triangle in the lower-right corner of
a cell. Smart tags lead to helpful options based on the contents of the cell. See
Excel Help for more information on smart tags.
The rst item in the list is just a statement of the problem. In this example, the
statement is Formula Omits Adjacent Cells. Sure enough, it does just that! But is it
an error? Did you mean to enter the extra value in cell B3? Perhaps it has some
other meaning or use.
The other items in the list give you options:
»
Update Formula to Include Cells: Automatically changes the formula to
include the extra cell in this example. So the formula in cell B10 changes from
=SUM(B4:B9) to =SUM(B3:B9). Of course, the calculated sum changes as well.
»
Help on This Error: Steers you to Excel’s Help system.
»
Ignore Error: Closes the list and returns you to the worksheet. The triangle is
removed from the cell in question. You’ve told Excel that you know what
you’re doing, and you want Excel to butt out. Good job!
»
Edit in Formula Bar: Places the cursor in the Formula Bar so you can easily
edit the formula.
»
Error Checking Options: Displays the Formulas tab of the Excel Options
dialog box (shown in Figure4-12). On this tab, you set options for how Excel
handles errors.
FIGURE4-11:
Deciding what to
do with the
possible error.
CHAPTER 4 Fixing Formula Boo-Boos 75
Auditing Formulas
With Excel, you can create some fairly complex solutions. A cell can contain a for-
mula that uses values from multitudes of other cells and ranges. Working through
long, complex formulas to track down problems can be quite tedious. The good
news is that Excel has a way to help!
Formulas may contain precedents and may serve as dependents to other
formulas:
»
Precedents are cells or ranges that aect the active cell’s value.
»
Dependents are cells or ranges aected by the active cell.
It’s all relative! A cell often serves as both a precedent and a dependent. Figure4-13
shows a simple worksheet with some values and some calculations. Cell B9 con-
tains the formula =SUM(B3:B8). Cell F9 contains the formula =SUM(F3:F8). Cell
B18 contains the formula =B9-F9.
»
Cells B3:B8 are precedents of B9, but at the same time, cell B9 is dependent
on all the cells in B3:B8.
FIGURE4-12:
Setting error-
handling options.
76 PART 1 Getting Started with Excel Formulas and Functions
»
Cells F3:F8 are precedents of F9, but at the same time, cell F9 is dependent on
all the cells in F3:F8.
»
Cells B9 and F9 are precedents of B18, but at the same time, cell B18 is
dependent on cells B9 and F9.
To help you follow and x formulas, Excel provides formula auditing tools. The
Formula Auditing group of the Formulas tab on the Ribbon has three buttons that
let you use formula auditing. Figure4-14 shows the worksheet from Figure4-13
with visible precedent and dependent lines. The methods for displaying these
lines are shown on the Ribbon.
Precedent and dependent lines are always inserted from or to the active cell. From
the active cell:
»
To see what other cells are referenced in the active cell’s formula, click the
Trace Precedents button.
»
To see which other cells contain a reference to the active cell, click the Trace
Dependents button.
The Remove Arrows drop-down menu has three choices:
»
Remove Arrows
»
Remove Precedent Arrows
»
Remove Dependent Arrows
FIGURE4-13:
Understanding
precedents and
dependents.
CHAPTER 4 Fixing Formula Boo-Boos 77
In Figure4-14, cells B9 and F9 have arrows that originate in the cells above. This
shows the ow of precedents into the given cells. The arrow head rests in the cell
that has the formula that contains the references of the precedents.
On the other hand, cells B9 and F9 themselves then have lines coming from them
and ending as arrow heads in cell B18. Therefore, B9 and F9 serve as precedents to
cell B18. Put another way, cell B18 is dependent on cells B9 and F9.
Double-clicking a tracer arrow activates the cell on one end of the line. Double-
clicking again activates the cell on the other end.
Tracing precedents and dependents can lead to some interesting conclusions
about a worksheet. Complex formulas can be dicult to follow, but by displaying
tracer arrows, you can better see what is going on. Figure4-15 shows a piece of a
worksheet used in a nancial solution. The active cell, H2, has a complex formula
in it, as you can see by looking at the Formula Bar. The tracer arrows show that
numerous precedents are feeding the formula in the active cell.
When a cell references a cell on a dierent worksheet, an icon that looks like a
worksheet appears at the end of the precedent line. This serves as a visual clue
that the formula is composed of values from more than the current worksheet.
The tracer arrows make it easy to see the values that are feeding the formula and,
therefore, make it easier to look for the source of a problem. For example, cell H2
may be returning a negative number as an answer. The formula adds certain val-
ues. Positive numbers added with a negative number may return a negative num-
ber as the result of the calculation. Therefore, just looking for a negative number
among the values at the end of the tracer arrows may help identify the problem,
perhaps within just a few seconds!
FIGURE4-14:
Tracing formulas.
78 PART 1 Getting Started with Excel Formulas and Functions
Watching the Watch Window
The Watch Window lets you watch the calculated results of a formula but without
the limitation of having the cell be in the viewing area of Excel. This feature is
helpful when you’re working on correcting formulas that use precedents that are
scattered about the worksheet or workbook.
First, to set up a watch, follow these steps:
1. Click the Watch Window button on the Formulas tab of the Ribbon.
2. In the Watch Window, click the Add Watch button.
The Add Watch dialog box opens.
3. Use the RefEdit control (the square button to the right of the entry box)
to specify the cell(s), or type in the cell address or range.
4. Click the Add button in the Add Watch dialog box to complete setting up
the watch.
Figure4-16 shows the Watch Window with a watch already in place. Cell C6 of the
Costs worksheet is being watched. The formula uses precedents from both the
Orders and Shipping worksheets. The Watch Window sits on top of the workbook
and stays visible regardless of which worksheet is active. This means, for exam-
ple, that you could try dierent values on the Orders worksheet and see the result
FIGURE4-15:
Examining the
components of a
complex formula.
CHAPTER 4 Fixing Formula Boo-Boos 79
in the calculation in Costs!C6, but without having to bounce around the work-
sheets to see how new values alter the calculated result.
The Watch Window also lets you delete a watch. That’s a good thing; otherwise,
you would end up with a bunch of watches you no longer need! To delete a watch,
perform these steps:
1. Select a watch from the list of watches in the Watch Window.
2. Click the Delete Watch button.
Evaluating and Checking Errors
The Evaluate Formula dialog box walks you through the sequential steps used in
calculating a result from a formula. These steps are useful for tracking down
errors in formulas that are long or have precedents. For example, the formula
=IF(MAX(Orders!B2:B29)>200,MAX(Orders!B2:B29)*Shipping!C22,Shippin
g!C24) refers to dierent worksheets. Using the Evaluate Formula dialog box
makes it easy to see how Excel works out this formula. The step-by-step approach
lets you see what is done at each step.
Figure4-17 shows the Evaluate Formula dialog box at the start of evaluating the
formula. To display the Evaluate Formula dialog box, simply click the Evaluate
Formula button in the Formula Auditing group of the Formulas tab of the Ribbon.
With each successive click of the Evaluate button, the Evaluation box displays the
interim results. The Step In and Step Out buttons are enabled during the steps that
work on the precedents.
The Evaluate Formula dialog box is great for really seeing how each little step
feeds into the nal calculated result. Using this dialog box lets you pinpoint exactly
where a complex formula has gone sour.
A similar error-hunting tool is the Error Checking dialog box, shown in Figure4-18.
(Excel really wants to help you!)
FIGURE4-16:
Using the Watch
Window to keep
an eye on a
formula’s result.
80 PART 1 Getting Started with Excel Formulas and Functions
Display the Error Checking dialog box by choosing Error Checking from the Error
Checking drop-down menu on the Ribbon (on the Formulas tab, of course).
The dialog box has a handful of buttons that let you analyze the error and make
decisions about it:
»
Help on This Error starts the Excel Help system.
»
Show Calculation Steps opens the Evaluate Formula dialog box.
»
Ignore Error ensures that Excel no longer cares about the error. The cell may
still display an error symbol, but Excel does not give a hoot, and you probably
won’t either, because you clicked the button.
»
Edit in Formula Bar places the cursor in the Formula Bar, making it easy for
you to edit the formula.
»
Options opens the Excel Options dialog box.
»
Previous and Next cycle through the multiple errors on the worksheet,
assuming that there is more than one error.
The Error Checking drop-down menu hosts the Trace Error command. Only prec-
edents are pointed out by the tracer lines. This makes it easy to see the cells that
feed into a cell that has an error.
FIGURE4-17:
Evaluating a
formula.
FIGURE4-18:
Checking the
cause of an error.
CHAPTER 4 Fixing Formula Boo-Boos 81
Making an Error Behave the
Way You Want
Excel has a neat function: IFERROR.Don’t confuse it with ISERROR, which is sim-
ilar but not as slick. Figure4-19 shows how IFERROR one-ups ISERROR.In the
gure, F7 has the dreaded Divide by Zero error. It’s not a pretty thing to see, and
I am sure the boss would appreciate a cleaner visual to work with.
Cell H7 has the tried-and-true way to make the error not look like an error. Using
the ISERROR function nested inside an IF function takes care of the error’s appear-
ance, as shown in cell H7 (which refers to cell F7). Cell H8 achieves the same result
with the IFERROR function. Cells J7 and J8, respectively, show the formulas that
are in cells H7 and H8.
»
In cell H7 is =IF(ISERROR(F7),0,F7+3).
»
In cell H8 is =IFERROR(F7+3,0).
The main distinction is that IFERROR, as a single function, does what used to take
two functions. I don’t know how many times the “keep it simple” approach has
been bantered around, but what the heck— aren’t we all for making our work
easier? With IFERROR, the rst argument is being tested. If the test makes sense,
Excel goes with it. Otherwise, the second argument is used.
IFERROR can return a message. For example, consider this: =IFERROR(F7+3,
"Somebody Goofed!").
FIGURE4-19:
Two ways to
prevent an error
from being seen.
2
Doing the Math
IN THIS PART ...
Get a handle on your loans.
Find out how to appreciate depreciation.
Review math basics.
Get math-savvy with some really cool functions.
CHAPTER 5 Calculating Loan Payments and InterestRates 85
Chapter5
Calculating Loan
Payments and
InterestRates
A penny saved is a penny earned. A penny by itself is not much. But add a
little savings here and there over the life of a loan, and the sum could be
signicant! Just think of what you can do with the extra money— extend
a vacation, give it to charity, or save it for a rainy day.
Taking out a car loan, a mortgage, or another type of loan involves planning how
you want to manage the loan payments. In the simplest terms, all you may need
to know is the amount of your monthly payment. But knowing the components of
a loan and being able to compare one loan with another can help you manage your
nancial resources in your own best interest.
Consider an auto loan, one of the most common loan types. The factors involved
include the cost of the vehicle, the down payment, the length of the loan, and the
interest rate. Excel can help you see how all these factors aect your bottom line,
letting you make the best decision (I would love to get a Ferrari, but a Hyundai will
have to do).
IN THIS CHAPTER
»
Formatting monetary values
»
Working with loan calculations
86 PART 2 Doing the Math
You can use the nancial functions in Excel to crunch the numbers for your loans.
You supply these functions the relevant numbers: the principal amount, the inter-
est rate, the period (how often you make a payment), and the length of the loan.
Then the functions return an answer, such as your payment amount. In this chap-
ter, I show you how to use these functions to turn your nance gures into mean-
ingful results.
The principal is the amount being borrowed. The interest rate is the annual
percentage that the lender charges for lending the money. Your total payments
equal the principal plus the sum of all interest charges.
Understanding How Excel Handles Money
Excel is a lot more than a simple adding machine. It has great tools for working
with money values, and a number of ways of presenting the amounts. For exam-
ple, Excel makes it easy for you to make sure that your nancial amounts are
displayed with two decimal points. You can even work with dierent currencies
from around the world.
Going with the cash ow
Excel works with money on a cash-ow basis. In other words, money amounts are
treated either as a cash ow in (money you receive) or a cash ow out (money you
pay out). Yes, there always seems to be too many of the latter and not enough of
the former— but, hey, you can’t blame Excel for that!
Excel represents cash ows in as positive numbers and cash ows out as negative
numbers. For example, when you calculate the payments on a loan, the situation
is as follows:
»
The amount of the loan is entered as a positive value, because this is the
money you’ll receive from the bank or whoever is giving you the loan.
»
The monthly payment that Excel calculates is a negative value, because this is
money that you’ll be paying out.
Formatting for currency
One of Excel’s shining strengths is accepting, manipulating, and reporting on
monetary data. As such, Excel provides robust formatting for numeric data,
including the ability to control the placement of commas and decimals, and even
how to format negative values.
CHAPTER 5 Calculating Loan Payments and InterestRates 87
People are used to seeing money amounts formatted with a currency symbol and
a certain number of decimal places. In the United States and Canada, that is the
dollar sign and two decimal places. Let’s face it— $199.95 looks like money, but
199.950 does not. Excel makes formatting cells to display money amounts as easy
as clicking a button. To format amounts as dollars, follow these steps:
1. Select the cell or cells you want to format.
2. Click the Dollar ($) button in the Number group of the Home tab on the
Ribbon.
This technique assigns Excel’s default Accounting format to the selected cells. In
the United States, the default currency format follows
»
A dollar sign, aligned to the left of the cell
»
Two decimal places
»
Negative numbers enclosed in parentheses
The default format depends on your locale, which is a setting of the operating
system. If you’re in Italy, for example, the locale should be set so that the default
currency format is the euro (€).
But suppose that you don’t want the default currency formatting. Perhaps you’re
in the United States and are working on a spreadsheet for the London oce. You
can specify the currency symbol, the number of decimal places, and how negative
values are shown by following these steps:
1. Select the cell or cells you want to format.
2. Right-click the cell(s) and choose Format Cells from the drop-down menu.
3. In the Format Cells dialog box, select the Number tab, as shown in
Figure5-1.
4. Click Currency in the Category list.
5. Select the desired number of decimal places with the Decimal Places
spinner control.
6. Select the desired currency symbol from the Symbol drop-down menu.
7. Select the desired format for negative numbers in the Negative Numbers
list.
8. Click OK to apply the formatting.
88 PART 2 Doing the Math
The Currency and Accounting formats are similar except for a couple of key points.
Currency provides choices for displaying negative values; Accounting uses one
xed display with parentheses. Currency places the currency symbol next to the
number; Accounting places the currency symbol at the left of the cell.
Choosing separators
When numbers are formatted as currency, two separator symbols are typically
used— one to separate thousands and the other to separate the decimal part of
the value. In the United States, commas are used for thousands and the period for
the decimal, as follows:
$12,345.67
Other countries have dierent ways of doing this. In many European countries, for
example, the period is used to separate thousands, and the comma is used for the
decimal. In addition, the currency symbol is often at the end of the number. An
amount in euros, for example, may be formatted as follows:
12.345,67€
In almost all situations, the operating system’s locale settings result in the auto-
matic use of the proper separators. If you need to change the separators from the
defaults, do so in the Regional and Language Options section of the Windows
FIGURE5-1:
Using the Format
Cells dialog box
to control
numeric display.
CHAPTER 5 Calculating Loan Payments and InterestRates 89
Control Panel. Note: These instructions are for computers running the Windows 10
operating system.
1. Type Control Panel in the Windows Search box on the Task Bar and click
Control Panel in the search results.
2. Click the Clock and Region link.
3. Click the Region link.
The Region dialog box opens (see Figure5-2).
4. Click the Additional Settings button to open the Customize Format
dialog box.
5. Select the Currency tab, as shown in Figure5-3.
6. Click OK or Cancel to close the Customize Format dialog box.
7. Click OK or Cancel again to close the Region dialog box.
You can change settings for numbers, currency, dates, and time in the Customize
Format dialog box.
FIGURE5-2:
Viewing regional
settings.
90 PART 2 Doing the Math
Figuring Loan Calculations
Loans are part of almost everyone’s life. At the personal level, you may need to
deal with car loans, education loans, and a mortgage. From a business perspective,
companies from the smallest to the largest often use loans to fund new equip-
ment, expansion, and so on. No matter what kind of loan you need, Excel has the
tools that permit you to evaluate loans and calculate specic details.
Most loans have the following ve factors:
»
Loan principal: This is the amount you’re borrowing. For example, if you’re
interested in a loan for $5,000, the loan principal is $5,000.
»
Interest rate: This is the cost to borrow the principal. This is how lenders
make money. The interest rate is a fee, so to speak, that a borrower pays to a
lender. Usually, but not always, the interest rate is expressed as a percent per
year.
»
Payment period: Loans are usually paid back by paying a periodic amount.
Most often, the period is monthly.
FIGURE5-3:
Customizing how
numeric values
are handled.
CHAPTER 5 Calculating Loan Payments and InterestRates 91
»
Duration of the loan: This is the count of payment periods. For example, a
loan may have 36 monthly payments.
»
Payment: This is the amount you pay each payment period.
Each of these factors is related to all the others. If you borrow more, your monthly
payments will be higher; that’s no surprise. If you get a low interest rate, you may
be able to pay o your loan in less time; that may be something to consider!
The functions used to calculate loan factors work with the same group of inputs,
namely the ve factors just listed. The functions typically accept three or four
inputs as data and then calculate the desired value, kind of like the way algebra
works.
Calculating the payment amount
The PMT function tells you the periodic payment amount for your loan. If you
know the principal, interest rate, and number of payments for a loan, you can use
the PMT function to calculate the payment amount. But rst, a word about inter-
est rates.
Most loan interest rates are expressed as an annual rate. However, Excel needs the
interest rate per payment period to calculate properly. For example, if you’re cal-
culating for a loan with monthly payments, you need the monthly interest rate.
You can easily get this number by dividing the annual interest rate by 12, the
number of months in a year. To calculate a loan payment, follow these steps:
1. Enter the loan principal, annual interest rate, and number of payment
periods in separate cells of the worksheet.
You can add labels to adjacent cells to identify the values, if desired.
2. Position the cursor in the cell where you want the results to display.
3. Type =PMT( to begin the function entry.
A small pop-up menu shows the arguments used in the function.
4. Click the cell where you entered the interest rate, or just type the cell
address.
5. Type /12 to divide the annual interest rate to get the monthly interest
rate.
6. Type a comma (,).
7. Click the cell where you entered the number of payments, or type the cell
address.
92 PART 2 Doing the Math
8. Type a comma (,).
9. Click the cell where you entered the principal amount, or type the cell
address.
10. Type ) and press Enter.
Watch those percentages! Remember that a percent is really one one-hundredth,
so 5 percent is the numerical value 0.05. You can format values to display as
percentages in Excel, but you must enter the proper value.
Figure5-4 shows how I set up a worksheet with values and returned the periodic
payment amount for a loan. The amount is expressed as a negative number
because payments are cash ow out. For example, you may be considering taking
out a loan from the bank for some house additions. Using real numbers, the loan
may be structured like this:
»
A loan amount of $15,000 (the principal)
»
An annual interest rate of 5 percent
»
A monthly payment period
»
A payment period of 24 payments
This summarizes four of the key parameters. The PMT function gures out the
fth: the periodic payment, which is the amount you have to shell out each month.
Although the PMT function returns the constant periodic payback amount for a
loan, note that each payment actually consists of two portions. One portion goes
toward reducing the principal, and the other portion is the interest payment. As if
this isn’t already confusing enough!
FIGURE5-4:
The PMT function
calculates the
loan payment
amount.
CHAPTER 5 Calculating Loan Payments and InterestRates 93
You may notice some new terms when using this function: Pv, Fv, and Nper. In
nancial terminology, present value (Pv) refers to the value of a transaction at the
present moment. When you’re dealing with a loan, for example, the present value
is the amount you receive from the loan— in other words, the principal. The term
future value (Fv) refers to the value of a transaction at some point in the future,
such as the amount you’ll accumulate by saving $50 a month for 5 years. Nper
stands for the number of payment periods in the loan.
Calculating interest payments
The IPMT function tells you the interest payment for a given period. In each pay-
ment period during a typical loan, the payment consists of a portion set to reduce
the principal of the loan, with the other portion of the payment being the interest
on the principal. The amount of interest varies payment by payment. In a typical
loan, the portion of the payment that is interest is highest in the rst period and
is reduced in each successive period.
The IPMT function takes four inputs: the principal, the interest rate, the number
of payments for the loan, and the number of the payment you’re interested in. For
example, a loan may have 24 payments, and you’re interested in how much inter-
est is included in the 12th payment. For some types of loans, the interest is tax
deductible, so this information may literally be worth something! Here are the
steps to use the IPMT function:
1. Enter the following information in separate cells in a column of the
worksheet:
•
Loan principal
•
Annual interest rate
•
Number of payment periods
•
Number of the actual period for which you want to calculate the interest
You can add labels to adjacent cells to identify the values, if desired.
2. Position the cursor in the cell where you want the results to appear.
3. Type =IPMT( to begin the function entry.
4. Click the cell where you entered the interest rate, or just type the cell
address.
5. Type /12.
This divides the annual interest rate to get the monthly interest rate.
6. Type a comma (,).
94 PART 2 Doing the Math
7. Click the cell where you entered the number of the payment to analyze,
or just type the cell address.
8. Type a comma (,).
9. Click the cell where you entered the number of payments, or just type
the cell address.
10. Type a comma (,).
11. Click the cell where you entered the principal amount, or just type the
cell address.
12. Type ) and press Enter.
The IPMT function returns the interest portion of the amount of the specied
payment. This amount is smaller than the full periodic payment amount. How
much smaller depends on which sequential payment is being examined. The
remainder of the payment— the part that is not interest— goes to reduce the
principal.
You can use two optional arguments with IPMT:
»
Future Value: This is the amount you want the loan to be worth at the end of
its life. The default is 0, meaning the loan is fully paid o.
»
Type: This tells the function whether payments are applied at the end of the
period or the beginning of the period. A value of 0 indicates the end of the
period. A value of 1 indicates the beginning of the period. The default is 0.
These optional arguments, when used, become the fth and sixth arguments,
respectively.
Calculating payments toward principal
The PPMT function tells you the payment on principal for a given period. In each
payment period during a typical loan, the payment consists of a portion that goes
toward reducing the principal of the loan and another portion that is interest.
With the PPMT function, you can nd out the amount that reduces the principal.
The ratio of the interest portion to the payment on principal portion varies pay-
ment by payment. In a typical loan, the portion of the payment that is interest is
highest in the rst period and is reduced in each successive period. Turning that
around, the last payment is almost all toward paying down the principal.
CHAPTER 5 Calculating Loan Payments and InterestRates 95
The PPMT function takes four inputs: the principal, the interest rate, the number
of payments for the loan, and the number of the payment in question. For exam-
ple, a loan may have 36 payments, and you’re interested in how much principal is
included in just the last payment. Here are the steps to use this function:
1. Enter the loan principal, the annual interest rate, the number of payment
periods, and the number of the actual period for which the interest is to
be calculated in separate cells within the worksheet.
You can add labels to adjacent cells to identify the values, if you want.
2. Position the cursor in the cell where you want the results to appear.
3. Type =PPMT( to begin the function entry.
4. Click the cell where you entered the interest rate, or just type the cell
address.
5. Type /12 to divide the annual interest rate to get the monthly interest
rate.
6. Type a comma (,).
7. Click the cell where you entered the number of the payment to analyze,
or just type the cell address.
8. Type a comma (,).
9. Click the cell where you entered the number of payments, or just type
the cell address.
10. Type a comma (,).
11. Click the cell where you entered the principal amount, or just type the
cell address.
12. Type ) and press Enter.
The PPMT function returns the amount of the payment that reduces the principal.
This amount is smaller than the full periodic payment amount. How much smaller
depends on which sequential payment is being examined. The remainder of the
payment, of course, is the interest charge.
The PMT function tells how much each payment is. The IPMT function tells you
the interest portion. The PPMT tells you the principal function. For any given pay-
ment period, the amounts returned by IPMT and PPMT should equal the amount
returned by PMT.
96 PART 2 Doing the Math
You can use two optional arguments with PPMT:
»
Future Value: This is the amount you want the loan to be worth at the end of
its life. The default is 0.
»
Type: This tells the function whether payments are applied at the end of the
period or the beginning of the period. A value of 0 indicates the end of the
period. A value of 1 indicates the beginning of the period. The default is 0.
These optional arguments, when used, become the fth and sixth arguments,
respectively.
Calculating the number of payments
The NPER function tells you how many payments are necessary to pay o a loan.
This is useful when you know how much you can aord to pay per month and
need to know how long it will take to pay o the loan. The inputs for this function
are the principal, the interest rate, and the periodic payment amount.
Here’s how to use the NPER function:
1. Enter the following in separate cells on your worksheet:
•
Loan principal
•
Annual interest rate
•
Periodic payment amount (the amount you can aord to pay)
Enter the periodic payment amount as a negative number because payments
are cash ow out. You can add labels to adjacent cells to identify the values, if
you want.
2. Position the cursor in the cell where you want the results to display.
3. Type =NPER( to begin the function entry.
4. Click the cell where you entered the interest rate, or just type the cell
address.
5. Type /12 to divide the annual interest rate to get the monthly interest
rate.
6. Type a comma (,).
7. Click the cell where you entered the periodic payment amount, or just
type the cell address.
8. Type a comma (,).
CHAPTER 5 Calculating Loan Payments and InterestRates 97
9. Click the cell where you entered the principal amount, or just type the
cell address.
10. Type ) and press Enter.
Figure5-5 shows how I set up a worksheet with values and used the NPER func-
tion to nd out how many payments are necessary to pay o a loan. In this exam-
ple, I assume you can aord to pay $200 per month for a loan. The amount you
need is $4,000, and you’re able to get a 6 percent interest rate.
With this set of assumptions, the NPER function returns a value of 21.12 months
to pay o the loan. I don’t think anyone will mind if you round that o to
21 months. Knowing you’ll pay o the loan in less than 2 years may very well
allow you to plan ahead for some other activity at that time. Did someone say
“Las Vegas”?
You can use two optional arguments with NPER:
»
Future Value: This is the amount you want the loan to be worth at the end of
its life. The default is 0.
»
Type: This tells the function whether payments are applied at the end of the
period or the beginning of the period. A value of 0 indicates the end of the
period. A value of 1 indicates the beginning of the period. The default is 0.
These optional arguments, when used, become the fth and sixth arguments,
respectively.
FIGURE5-5:
The NPER
function
calculates the
number of
payments for a
loan.
98 PART 2 Doing the Math
Calculating the number of payments
with PDURATION
This function is a twist on determining the number of payments. Instead of using
a periodic payment amount in the calculation, PDURATION uses the present value
of the loan (the borrowed amount) and the future value of the loan (what you will
have paid in total when the loan is paid o). This calculation is useful if and when
you know just three pieces of information:
»
The loan principal
»
Annual interest rate
»
The amount paid back (the combined principal and interest)
The result PDURATION gives you is the number of periods based on the previously
listed factors.
Here’s how to use the PDURATION function:
1. Enter the following in separate cells of your worksheet:
•
Loan principal
•
Annual interest rate
•
The expected total amount you will have paid back at the end of the loan
2. Position the cursor in the cell where you want the results to display.
3. Type =PDURATION( to begin the function entry.
4. Click the cell where you entered the interest rate, or just type the cell
address.
5. Type /12 to divide the annual interest rate to get the monthly interest
rate.
6. Type a comma (,).
7. Click the cell where you entered the principal, or just type the cell
address.
8. Type a comma (,).
9. Click the cell where you entered the payback amount, or just type the
cell address.
10. Type ) and press Enter.
CHAPTER 5 Calculating Loan Payments and InterestRates 99
Figure5-6 shows how I set up a worksheet with values and used the PDURATION
function to nd out how many payments are necessary to pay o a loan. In this
example, I assume that the amount paid o is $4,400 (includes principal and
interest). The amount borrowed is $4,000, and the annual interest rate is 6 percent.
The number of payments is 22.92, so I’ll call that 23 payments — just under
2 years.
Calculating the interest rate
The RATE function tells you what the interest rate is on a loan. This function is
great for comparing loan oers. Although a loan oer always includes an interest
rate, you may want to use Excel to double-check to ensure that some other fees
are not included in the payments. Then you can compare dierent loan scenarios
to see which one oers the true lowest interest rate. I don’t think anyone wants to
pay more than necessary!
Some lenders charge fees as well as an annual interest rate. When these fees are
gured in, the eective interest rate will be higher than the stated interest rate. You
can use the RATE function to determine the eective interest rate for a loan. If it’s
the same as the stated interest rate, you know no fees are being added.
The inputs for this function are the principal, the number of payments, and the
xed amount of the periodic payment. Here’s how to use the RATE function:
1. Enter the following in separate cells of the worksheet:
•
Loan principal
•
Number of payment periods
•
Amount you will pay each month
FIGURE5-6:
The PDURATION
function
calculates the
number of
payments for a
loan.
100 PART 2 Doing the Math
Enter the monthly payment amount as a negative number because it is cash
ow out. You can add labels to adjacent cells to identify the values, if you want.
2. Position the cursor in the cell where you want the results to appear.
3. Type =RATE( to begin the function entry.
4. Click the cell where you entered the number of periods, or just type the
cell address.
5. Type a comma (,).
6. Click the cell where you entered the monthly payment amount, or just
type the cell address.
7. Type a comma (,).
8. Click the cell where you entered the principal amount, or just type the
cell address.
9. Type ) and press Enter.
The RATE function returns the interest rate per period. This number can be mis-
leading. The periodic interest amount may be small enough that it is displayed as
0 percent if the formatting in the cell isn’t set to display enough decimal points.
To nd out the annual rate, you simply need to take the number returned by RATE
and multiply it by 12. To do this, follow these steps:
1. Position the cursor in the cell where you want the annual interest rate to
appear.
2. Type =.
3. Click the cell where the RATE function returned the periodic interest rate.
4. Type *.
5. Type 12.
6. Press Enter.
As an example, assume a loan principal of $15,000 with a monthly payment of
$650. The loan is to be paid o in 24 months. Figure5-7 shows a worksheet with
these gures. The periodic interest rate is calculated with the RATE function, and
the annual rate is calculated by multiplying the periodic interest rate by 12.
CHAPTER 5 Calculating Loan Payments and InterestRates 101
You can use three optional arguments with RATE:
»
Future Value: This is the amount you want the loan to be worth at the end of
its life. The default is 0.
»
Type: This tells the function whether payments are applied at the end of the
period or the beginning of the period. A value of 0 indicates the end of the
period. A value of 1 indicates the beginning of the period. The default is 0.
»
Guess: This estimates what the interest rate should be. It is possible that the
function will need this value to determine a result. (See Excel’s Help system for
further information.) The default value is 0.1 (for 10 percent).
These optional arguments, when used, become the fourth, fth, and sixth argu-
ments, respectively.
Calculating the principal
The PV function tells you what the principal amount of a loan is when you know
the other loan factors, such as the interest rate and the number of payment peri-
ods. You can use PV to determine how much you can borrow when you already
know how much you can pay each month and how long you can make payments.
The inputs for this function are the interest rate, the number of payment periods,
and the monthly payment amount. The interest rate used in the function is the
periodic rate, not the annual rate. Here’s how to use the PV function:
1. Enter the following in separate cells of your worksheet:
•
Annual interest rate
•
Number of payment periods
•
Periodic payment amount
FIGURE5-7:
The RATE
function
calculates the
periodic interest
rate.
102 PART 2 Doing the Math
Enter the periodic payment amount as a negative number because payments
are cash ow out. You can add labels to adjacent cells to identify the values, if
desired.
2. Position the cursor in the cell where you want the results to appear.
3. Type =PV( to begin the function entry.
4. Click the cell where you entered the interest rate, or just type the cell
address.
5. Type /12 to divide the annual interest rate to get the monthly interest
rate.
6. Type a comma (,).
7. Click the cell where you entered the number of payments, or just type
the cell address.
8. Type a comma (,).
9. Click the cell where you entered the periodic payment amount, or just
type the cell address.
10. Type ) and press Enter.
As an example, assume a monthly payment amount of $600. The annual interest
rate is 5 percent. There are 24 monthly payments. Figure5-8 shows a worksheet
with these gures.
FIGURE5-8:
The PV function
calculates the
principal amount
of a loan.
CHAPTER 5 Calculating Loan Payments and InterestRates 103
With these assumptions, the loan principal is $13,676. Altering any of the param-
eters causes PV to return a dierent amount of principal. For example, raising the
interest rate to 7.5 percent tells you that you can borrow only $13,333. Although
you may often think about how much you’re borrowing, having interest in the
interest is just as important!
You can use two optional arguments with PV:
»
Future Value: This is the amount you want the loan to be worth at the end of
its life. The default is 0.
»
Type: This value tells the function whether payments are applied at the end of
the period or the beginning of the period. A value of 0 indicates the end of the
period. A value of 1 indicates the beginning of the period. The default is 0.
These optional arguments, when used, become the fth and sixth arguments,
respectively.
CHAPTER 6 Appreciating What You’ll Get, Depreciating What You’ve Got 105
Chapter6
Appreciating What You’ll
Get, Depreciating What
You’ve Got
Money makes the world go round, so the saying goes. I have a new one:
Excel functions make the money go round. Excel has functions that let
you gure out what an investment will be worth at a future date. We all
know it’s a good thing to look for a good interest rate on an investment. With the
FV (Future Value) function, you can take this a step further and know how much
the investment will be worth down the road.
Have you ever wondered what to do with some extra money? You can put it in the
bank, you can pay o a debt, or you can purchase something. Excel helps you g-
ure out the best course of action by using the IRR (Internal Rate of Return) func-
tion. The IRR function lets you boil down each option to a single value that you can
then use to compare opportunities and select the best one.
For the business set, Excel has a number of functions to help create depreciation
schedules. Look no further than the SLN, SYD, DB, and DDB functions for help in
this area. Brush up on these, and you can talk shop with your accountant!
IN THIS CHAPTER
»
Determining what an investment is
worth
»
Using dierent depreciation methods
»
Evaluating business opportunities
106 PART 2 Doing the Math
SLN is a function used to calculate straight-line deprecation. SYD is a function to
calculate sum-of-years’-digits depreciation. DB and DDB are variations of the
declining-balance method of depreciation.
Looking into the Future
The FV function tells you what an investment will be worth in the future. The
function takes an initial amount of money and also takes into account additional
periodic xed payments. You also specify a rate of return— the interest rate—
and the returned value tells you what the investment will be worth after a speci-
ed period of time.
For example, you start a savings account with a certain amount, say $1,000.
Every month you add $50 to the account. The bank pays an annual interest rate of
5 percent. At the end of 2 years, what is value of the account?
This is the type of question the FV function answers. The function takes ve
arguments:
»
Interest rate: This argument is the annual interest rate. When entered
in the function, it needs to be divided by the number of payments per
year— presumably 12, if the payments are monthly.
»
Number of payments: This argument is the total number of payments in
the investment. These payments are the ones beyond the initial investment;
don’t include the initial investment in this gure. If payments occur monthly
and the investment is for 3 years, there are 36 payments.
»
Payment amount: This argument is the xed amount contributed to the
investment each payment period.
»
Initial investment (also called present value, or PV): This argument is the
amount the investment starts with. A possible value is 0, which means no
initial amount is used to start the investment. This is an optional argument.
If left out, 0 is assumed.
»
How payments are applied: The periodic payments may be applied at either
the beginning of each period or the end of each period. This argument aects
the result to a small but noticeable degree. Either a 0 or a 1 can be entered. A
0 tells the function that payments occur at the end of the period. A 1 tells the
function that payments occur at the start of the period. This is an optional
argument. If it’s left out, 0 is assumed.
CHAPTER 6 Appreciating What You’ll Get, Depreciating What You’ve Got 107
When using the FV function, be sure to enter the initial investment amount
and the periodic payment amount as negative numbers. Although you’re investing
these monies, you’re essentially paying out (even if it’s into your own account).
Therefore, these are cash ows out.
Here’s how to use the FV function:
1. Type the following data in separate cells of the worksheet:
•
Annual interest rate
•
Number of payment periods
•
Periodic payment amount
•
Initial investment amount
You can add labels to adjacent cells to identify the values, if desired.
2. Position the cursor in the cell where you want the results to appear.
3. Type =FV( to begin the function entry.
4. Click the cell where you typed the annual interest rate, or type the cell
address.
5. Type /12 to divide the annual interest rate to get the monthly interest
rate.
6. Type a comma (,).
7. Click the cell where you typed the total number of payments, or type the
cell address.
8. Type a comma (,).
9. Click the cell where you typed the periodic payment amount, or type the
cell address.
10. Type a comma (,).
11. Click the cell where you typed the initial investment amount, or type the
cell address.
12. (Optional) Type a comma (,) and then type either 0 or 1 to identify
whether payments are made at the beginning of the period (0) or at the
end of the period (1).
13. Type ) and press Enter.
Figure6-1 shows how much an investment is worth after 2 years. The investment
is begun with $1,000, and $50 is added each month. The interest rate is 5 percent.
The value of the investment at the end is $2,364.24. The actual layout was $2,200
($1,000 + [$50 × 24]). The account has earned $164.24.
108 PART 2 Doing the Math
Depreciating the Finer Things in Life
Depreciation is the technique of allocating the cost of an asset over the useful
period that the asset is used. Depreciation is applied to capital assets, which are
tangible goods that provide usefulness for a year or more.
Vehicles, buildings, and equipment are the types of assets that depreciation can be
applied to. A tuna sandwich is not a capital asset because its usefulness is going to
last for just the few minutes it takes someone to eat it— although the person eat-
ing it may expect to capitalize on it!
Take the example of a business purchasing a delivery truck. The truck costs
$35,000. It’s expected to be used for 12 years; this is known as the life of the asset.
At the end of 12 years, the vehicle’s estimated worth will be $8,000. These gures
follow certain terminology used in the depreciation formulas:
»
Cost: This is the initial cost of the item ($35,000). This could include not just
the price of the item, but also costs associated with getting and installing the
item, such as delivery costs.
»
Salvage: This is the value of the item at the end of the useful life of the item
($8,000).
»
Life: This is the number of periods that the depreciation is applied to. This is
usually expressed in years (in this case, 12 years).
Depreciation is calculated in dierent ways. Some techniques assume that an
asset provides the majority of its usefulness during the early periods of its life.
Depreciation in this case is applied on a sliding scale from the rst period to the
last. The bulk of the depreciation gets applied in the rst few periods. This is
known as an accelerated depreciation schedule. Sometimes, the depreciation amount
FIGURE6-1:
Earning extra
money in an
investment.
CHAPTER 6 Appreciating What You’ll Get, Depreciating What You’ve Got 109
runs out sooner than the asset’s life. Alternatively, depreciation can be applied
evenly over all the periods. In this case, each period of the asset’s life has an equal
amount of depreciation to apply. The dierent depreciation methods are summa-
rized in Table6-1.
The depreciable cost is the original cost minus the salvage value.
Figure6-2 shows a worksheet with a few dierent methods. The methods use the
example of a delivery truck that costs $35,000, is used for 12 years, and has an
ending value of $8,000. An important calculation in all these methods is the
depreciable cost, which is the original cost minus the salvage value. In this exam-
ple, the depreciable cost is $27,000, calculated as $35,000– $8,000.
In the three depreciation methods shown in Figure6-2— Straight Line, Sum of
Years’ Digits, and Double Declining Balance — all end with the accumulated
depreciation at the end of life equal to the depreciable cost, or the cost minus the
salvage.
However, each method arrives at the total in a dierent way. The Straight Line
method simply applies an even amount among the periods. The Sum of Years’
Digits and Double Declining Balance methods accelerate the depreciation. In fact
the Double Declining Balance method does it to such a degree that all the depre-
ciation is accounted for before the asset’s life is over.
TABLE6-1 Depreciation Methods
Method Comments
Excel Function
That Uses
the Method
Straight Line Evenly applies the depreciable cost (Cost– Salvage)
among the periods. Uses the formula (Cost–
Salvage) ÷ Number of Periods.
SLN
Sum of
Years’ Digits
First sums up the periods, literally. For example,
if there are ve periods, the method rst calculates
the sum of the years’ digits as 1 + 2 + 3 + 4 + 5 = 15.
This method creates an accelerated depreciation
schedule. See Excel Help for more information.
SYD
Double
Declining
Balance
Creates an accelerated depreciation schedule by
doubling the straight-line depreciation rate but
then applies it to the running declining balance of
the asset cost, instead of to the xed depreciable
cost.
DDB, DB
110 PART 2 Doing the Math
Calculating straight-line depreciation
The SLN function calculates the depreciation amount for each period of the life of
the asset. The arguments are simple: just the cost, salvage, and the number of
periods. In Figure 6-2, each cell in the range D9:D20 has the same formula:
=SLN($B$2,$B$3,$B$4). Because straight-line depreciation provides an equal
amount of depreciation to each period, it makes sense that each cell uses the for-
mula verbatim. The answer is the same regardless of the period. (This approach
diers from the accelerated depreciation methods that follow.)
Using dollar signs ($) in front of column and row indicators xes the cell address
so it won’t change.
Here’s how to use the SLN function:
1. Type three values in a worksheet:
•
Cost of an asset
•
Salvage value (always less than the original cost)
•
Number of periods in the life of the asset (usually, years)
2. Type =SLN( to begin the function entry.
3. Click the cell that has the original cost, or type its address.
4. Type a comma (,).
FIGURE6-2:
Depreciating
an asset.
CHAPTER 6 Appreciating What You’ll Get, Depreciating What You’ve Got 111
5. Click the cell that has the salvage amount, or type its address.
6. Type a comma (,).
7. Click the cell that has the number of periods, or type its address.
8. Type ) and press Enter.
The returned value is the amount of depreciation per period. Each period has the
same depreciation amount. The same formula, referencing the same cells (using
$ for absolute referencing), is in each cell in the D9:D20 range.
Creating an accelerated
depreciation schedule
The SYD function creates an accelerated depreciation schedule (that is, more
depreciation is applied in the early periods of the asset’s life). The method uses an
interesting technique of rst summing up the years’ digits. So for a depreciation
schedule that covers 5 years, a value of 15 is rst calculated as 1 + 2 + 3 + 4 + 5 = 15.
If the schedule is for 10 years, the rst step of the method is to calculate the sum
of the digits 1 through 10, like this: 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = 55.
Then the years’-digit sum is used as the denominator in calculations with the
actual digits themselves to determine a percentage per period. The digits in the
calculations are the reverse of the actual periods. In other words, in a 5-year
depreciation schedule, the depreciation for the rst period is calculated as (5 ÷ 15) ×
Depreciable Cost. The second-period depreciation is calculated as (4 ÷ 15) × Depre-
ciable Cost. The following table makes it clear, with an assumed 5-year deprecia-
tion on a depreciable cost of $6,000, and a salvage value of $0:
Period Calculation Result
1() × 6,000 $2,000
2() × 6,000 $1,600
3() × 6,000 $1,200
4() × 6,000 $800
5() × 6,000 $400
Guess what? You don’t even need to know how this works! Excel does all the
guring for you. The SYD function takes four arguments: the cost, the salvage, the
life (the number of periods), and the period to be calculated.
112 PART 2 Doing the Math
SYD returns the depreciation for a single period. Earlier in this chapter, I show you
that the SLN function also returns the depreciation per period, but because all
periods are the same, the SLN function doesn’t need to have an actual period
entered as an argument.
The SYD function returns a dierent depreciation amount for each period, so the
period must be entered as an argument. In Figure6-2, each formula in the range
F9:F20 uses the SYD function but has a dierent period as the fourth argument.
For example, cell F9 has the formula =SYD($B$2,$B$3,$B$4,B9), and cell F10 has
the formula =SYD($B$2,$B$3,$B$4,B10). The last argument provides a dierent
value.
Here’s how to use the SYD function to calculate the depreciation for one period:
1. Type three values in a worksheet:
•
Cost of an asset
•
Salvage value (always less than the original cost)
•
Number of periods in the life of the asset (usually, years)
2. Type =SYD( to begin the function entry.
3. Click the cell that has the original cost, or type its address.
4. Type a comma (,).
5. Click the cell that has the salvage amount, or type its address.
6. Type a comma (,).
7. Click the cell that has the number of periods, or type its address.
8. Type a comma (,).
9. Type a number for the period for which to calculate the depreciation.
10. Type ) and press Enter.
The returned value is the amount of depreciation for the entered period. To calcu-
late the depreciation for the entire set of periods, type a formula with the SYD
function in the same number of cells as there are periods. In this case, each cell
has a dierent period entered for the fourth argument. To make this type of entry
easy to do, type the rst three arguments as absolute cell addresses. In other
words, use the dollar sign ($) in front of the row and column indicators. Leave the
fourth argument in the relative address format.
In cell F9in Figure6-2, the formula is =SYD($B$2,$B$3,$B$4,B9). Note that the
rst three arguments are xed to the cells B2, B3, and B4. With this formula
CHAPTER 6 Appreciating What You’ll Get, Depreciating What You’ve Got 113
entered in cell F9, simply dragging the formula (using the ll handle in the lower-
right corner of the cell) down to F20 lls the range of cells that need the calcula-
tion. The fourth argument changes in each row. For example, cell F20 has this
formula: =SYD($B$2,$B$3,$B$4,B20).
Creating an even faster accelerated
depreciation schedule
The Double Declining Balance method provides an accelerated depreciation sched-
ule but calculates the amounts dierently from the Sum of Years’ Digits method.
Although rooted in the doubling of the Straight Line method (which is not an
accelerated method), the calculation for each successive period is based on the
remaining value of the asset after each period instead of to the depreciable cost.
Because the remaining value is reduced each period, the schedule for each period
is dierent.
The DDB function takes ve arguments. The rst four are required:
»
Cost
»
Salvage
»
Life (the number of periods)
»
Period for which the depreciation is to be calculated
The fth argument is the factor. A factor of 2 tells the function to use the Double
Declining Balance method. Other values can be used, such as 1.5. The factor is the
rate at which the balance declines. A smaller value (than the default of 2) results
in a longer time for the balance to decline. When the fth argument is omitted, the
value of 2 is the default.
The DDB function returns a dierent depreciation amount for each period, so the
period must be typed as an argument. In Figure6-2, each formula in the range
H9:H20 uses the DDB function but has a dierent period as the fourth argument.
For example, cell H9 has the formula =DDB($B$2,$B$3,$B$4,B9) and cell H10 has
the formula =DDB($B$2,$B$3,$B$4,B10). The last argument provides a dierent
value.
As shown in Figure 6-2, earlier in this chapter, the Double Declining Balance
method provides an even more accelerated depreciation schedule than the Sum of
Years’ Digits method does. In fact, the depreciation is fully accounted for before
the asset has reached the end of its life.
114 PART 2 Doing the Math
Here’s how to use the DDB function to calculate the depreciation for one period:
1. Type three values in a worksheet:
•
Cost of an asset
•
Salvage value (always less than the original cost)
•
Number of periods in the life of the asset (usually, years)
2. Type =DDB( to begin the function entry.
3. Click the cell that has the original cost, or type its address.
4. Type a comma (,).
5. Click the cell that has the salvage amount, or type its address.
6. Type a comma (,).
7. Click the cell that has the number of periods.
8. Type a comma (,).
9. Type a number for the period for which to calculate the depreciation.
10. If a variation on the Double Declining Balance method is desired, type a
comma (,) and a value other than 2.
11. Type ) and press Enter.
The returned value is the amount of depreciation for the entered period. To calcu-
late the depreciation for the entire set of periods, you need to type a formula with
the DDB function in the same number of cells as there are periods. In this case,
each cell would have a dierent period entered for the fourth argument. One of the
best approaches is to use absolute addressing for the rst three function argu-
ments. Then, when you ll the rest of the cells by dragging or copying, the refer-
ences to original cost, salvage amount, and number of periods stay constant. You
can see an example of absolute addressing in the Formula Bar in Figure6-2.
There is no hard-and-fast rule for selecting the best depreciation method. How-
ever, it makes sense to use one that matches the depreciating value of the asset.
For example, cars lose a good deal of their value in the rst few years, so applying
an accelerated depreciation schedule makes sense.
Calculating a midyear depreciation
schedule
Most assets are not purchased, delivered, and put into service on January 1. Excel
provides a depreciation function, DB, that accounts for the periods being oset
CHAPTER 6 Appreciating What You’ll Get, Depreciating What You’ve Got 115
from the calendar year. The DB function takes ve arguments. The rst four are
the typical ones: the cost, the salvage, the life (the number of periods), and the
period for which the depreciation is to be calculated. The fth argument is the
number of months in the rst year. The fth argument is optional; when it’s left
out, the function uses 12 as a default.
For the fth argument, a value of 3 means the depreciation starts in October
(October through December is 3 months), so the amount of depreciation charged
in the rst calendar year is small. A value of 11 means that the depreciation starts
in February (February through December is 11 months).
Figure6-3 shows a depreciation schedule created with the DB function. Note that
the life of the asset is 12 years (in cell B4) but that the formula is applied to 13 dif-
ferent periods. Including an extra year is necessary because the rst year is par-
tial. The remaining months must spill into an extra calendar year. The depreciation
periods and the calendar years are oset.
The example in Figure 6-3 is for an asset put into service in August. Cell D9
has the formula =DB($B$2,$B$3,$B$4,B9,5). The fth argument is 5, which
indicates that the rst-year depreciation covers 5 months: August, September,
October, November, and December.
FIGURE6-3:
Osetting
depreciation
periods from the
calendar.
116 PART 2 Doing the Math
Here’s how to use the DB function to calculate the depreciation for one period:
1. Type three values in a worksheet:
•
Cost of an asset
•
Salvage value (always less than the original cost)
•
Number of periods in the life of the asset (usually, years)
2. Type =DB( to begin the function entry.
3. Click the cell that has the original cost, or type its address.
4. Type a comma (,).
5. Click the cell that has the salvage amount, or type its address.
6. Type a comma (,).
7. Click the cell that has the number of periods.
8. Type a comma (,).
9. Type a number for the period for which to calculate the depreciation.
10. Type a comma (,).
11. Type the number of months within the rst year that the depreciation is
applied to.
12. Type ) and press Enter.
The returned value is the amount of depreciation for the entered period. To calcu-
late the depreciation for the entire set of periods, you need to type a formula with
the DB function in the same number of cells as there are periods. However, you
should make space for an additional period (refer to Figure6-3).
Type the constant arguments of the function with absolute addressing (the dollar
signs used in front of row numbers or column letters). This makes the function
easy to apply across multiple cells by copying the formula. The references to the
pertinent function arguments stay constant.
Measuring Your Internals
Which is better to do: pay o your credit card or invest in Uncle Ralph’s new busi-
ness venture? You’re about to nance a car. Should you put down a large down
payment? Or should you put down a small amount and invest the rest? How can
you make decisions about alternative nancial opportunities like these?
CHAPTER 6 Appreciating What You’ll Get, Depreciating What You’ve Got 117
The internal rate of return (IRR) method helps answer these types of questions.
The IRR function analyzes the cash ows in and out of an investment and calcu-
lates an interest rate that is the eective result of the cash ows. In other words,
all the various cash ows are accounted for, and one interest rate is returned.
Then you can compare this gure with other nancial opportunities.
Perhaps Uncle Ralph’s business venture will provide a 10 percent return on your
investment. On the other hand, the credit card company charges you 12 percent on
your balance. In this case, paying o the credit card is wiser. Why? Because earn-
ing 10 percent is pointless when you’re just losing 12 percent elsewhere. Uncle
Ralph will understand, won’t he?
The IRR function takes two arguments. The rst is required; the second is optional
in some situations and required in others.
The rst argument is an array of cash ows. Following the cash-ows standard,
money coming in is entered as a positive value, and money going out is entered as
a negative value. Assuming that the particular cash ows in and out are entered
on a worksheet, the rst argument to the function is the range of cells.
The second argument is a guess at what the result should be. I know this sounds
crazy, but Excel may need your help here (though most times, it won’t). The IRR
function works by starting by guessing the result and calculating how closely the
guess matches the data. Then it adjusts the guess up or down and repeats the
process (a technique called iteration) until it arrives at the correct answer. If Excel
doesn’t gure it out in 20 tries, the #NUM! error is returned. In this case, you
could type a guess in the function to help it along. For example, 0.05 indicates a
guess of 5 percent, 0.15 indicates a guess of 15 percent, and so on. You can type a
negative number, too. For example, typing –0.05 tells the function that you expect
a 5 percent loss. If you don’t type a guess, Excel assumes 0.1 (10 percent).
Figure6-4 shows a business venture that has been evaluated with IRR.The proj-
ect is to create and market t-shirts. Assorted costs such as paying artists are cash
ows out, typed as negative numbers. The one positive value in cell B7 is the
expected revenue.
The IRR function has been used to calculate an expected rate of return. The for-
mula in cell B10 is =IRR(B3:B7). The entered range includes all the cash ows, in
and out.
This project has an internal rate of return of 12 percent. By the way, the invest-
ment amount in this case is the sum of all the cash ows out: $8,400. Earning
back $11,960 makes this a good investment. The revenue is signicantly higher
than the outlay.
118 PART 2 Doing the Math
Even though a business opportunity seems worthy after IRR has been applied, you
must consider other factors. For example, you may have to borrow the money to
invest in the business venture. The real number to look at is the internal rate of
return of the business venture less the cost of borrowing the money to invest.
However, the project can now be compared with other investments. Another proj-
ect may calculate to a higher internal rate of return. Then the second project would
make sense to pursue. Of course, don’t forget the fun factor. Making t-shirts may
be worth giving up a few extra points!
When you’re comparing opportunities with the IRR function, a higher returned
value is a better result than a lower internal rate of return.
Figure6-5 compares the business venture in Figure6-4 to another investment
opportunity. The second business venture is a startup videography business for
weddings and other aairs. There is a signicant outlay for equipment and mar-
keting. An internal rate of return is calculated for the rst year, and then for the
rst and second year together. Cell H10 has the formula =IRR(H3:H5), and cell H11
has the formula =IRR(H3:H6). It’s clear that even within the rst year, the second
business venture surpasses the rst.
FIGURE6-4:
Calculating the
return on a
business venture.
FIGURE6-5:
Comparing
business
opportunities.
CHAPTER 6 Appreciating What You’ll Get, Depreciating What You’ve Got 119
This is how to use the IRR function:
1. Type a series of cash-ow values:
•
Money paid out, such as the initial investment, as a negative value
•
Money coming in, such as revenue, as a positive value
2. Type =IRR( to begin the function entry.
3. Drag the cursor over the range of cells containing the cash ows, or type
the range address.
4. (Optional) Type a guess to help the function.
To do this, type a comma (,) and then type a decimal value to be used as a
percentage (such as 0.2 for 20 percent). You can type a positive or negative
value.
5. Type ) and press Enter.
Considering that internal rate of return is based on cash ows, in and out, it’s
prudent to include paying yourself, as well as accounting for investments back in
the business. Salary is cash ow out; investment is cash ow in.
Figure6-6 expands on the videography business with a detailed example. As a
business, it has various cash ows in and out— investment, utility payments,
professional fees (to the accountant and lawyer), advertising, salary, and so on.
FIGURE6-6:
Calculating
internal rate of
return with
several cash
ows.
120 PART 2 Doing the Math
The internal rate of return for the rst 3 months of the business is displayed in cell
E1. The formula is =IRR(B4:B25,-0.2). By the way, this one needed a guess to
return the answer. The guess is –0.2. The internal rate or return is –6 percent.
The videography business is not a moneymaker after a few months, but this is
true of many startups.
Note that this example includes dates. The IRR function works with an assump-
tion that cash ows are periodic, which they aren’t in this example. Another func-
tion, XIRR, handles dates in its calculation of the internal rate of return.
CHAPTER 7 Using Basic Math Functions 121
Chapter7
Using Basic Math
Functions
Excel is excellent for working with advanced math and complex calculations.
You can do so many complex things with Excel that it’s easy to forget that
Excel is great at basic math, too.
Need the sum of a batch of numbers? No problem. Need to round a number? Read
on! In this chapter, I show you not just how to sum and round numbers, but also
how to use these methods in ways that give you just the answers you need.
Adding It All Together with the SUM
Function
Just adding numbers together is something Excel is great at. Oh, you can use your
calculator to add numbers as well, but think about it: On a calculator you enter a
number, then press the + button, then enter another number, then press the +
button, and so on. Eventually you press the = button, and you get your answer. But
if you made an entry mistake in the middle, you have to start all over!
IN THIS CHAPTER
»
Summing, rounding, and truncating
values
»
Using a value’s sign in a calculation
»
Removing the sign from a number
122 PART 2 Doing the Math
The SUM function in Excel adds numbers together in a more ecient way. First,
you list all your numbers on the worksheet. You can see them all and verify that
they’re correct. Then you use the SUM function to add them all together. Here’s how:
1. Type some numbers in a worksheet.
These numbers can be both integer and real (decimal) values. You can add
labels to adjacent cells to identify the values, if you want.
2. Position the cursor in the cell where you want the results to appear.
3. Type =SUM( to begin the function entry.
4. Click a cell where you typed a number.
5. Type a comma (,).
6. Click a cell where you typed another number.
7. Repeat steps 5 and 6 until all the numbers have been typed into the
function.
8. Type ) and press Enter.
Figure7-1 shows an example of how these steps help sum up amounts that are not
situated next to one another on a worksheet. Cell F6 contains the sum of values in
cells C2, E2, G2, and I2.
Using SUM is even easier when the numbers you’re adding are next to one another
in a column or row. The SUM function lets you type a range of cells in place of
single cells in the arguments of the function. So adding a list of contiguous num-
bers is as easy as giving SUM a single argument. Here’s how you type a range as a
single argument:
1. Type some numbers in a worksheet.
Be sure the numbers are contiguous in a row or column. You can add labels to
adjacent cells to identify the values, if desired, but this doesn’t aect the SUM
function.
FIGURE7-1:
Using the SUM
function to add
noncontiguous
numbers.
CHAPTER 7 Using Basic Math Functions 123
2. Position the cursor in the cell where you want the results to appear.
3. Type =SUM( to begin the function entry.
4. Type the range address that contains the numbers.
Alternatively, you can click the rst cell with a number, hold down the left
mouse button, and drag the mouse over the range of cells.
5. Type ) and press Enter.
Using a range address in the function is a real timesaver— and is easier on the
ngers, too. Figure7-2 shows how a single range is used with the SUM function.
Look at the Formula Bar, and you’ll see that the entire function’s syntax is
=SUM(B6:B12). A single range takes the place of multiple individual cell addresses.
You can sum multiple ranges in a single formula, which is great when multiple
distinct contiguous cell ranges all must feed a grand total. Figure7-3 shows just
such a situation.
Here’s how you use SUM to add the values in multiple ranges:
1. Type some lists of numbers in a worksheet.
You can add labels to adjacent cells to identify the values, if desired.
2. Position the cursor in the cell where you want the results to appear.
3. Type =SUM( to begin the function entry.
4. Click the rst cell in a range, hold down the left mouse button, drag the
mouse over all the cells in the range, and then release the mouse button.
FIGURE7-2:
Calculating a sum
from a range of
cells.
124 PART 2 Doing the Math
5. Type a comma (,).
6. Click the rst cell in another range, hold down the left mouse button,
drag the mouse over all the cells in this range, and then release the
mouse button.
7. Repeat steps 5 and 6 until all the ranges have been typed into the
function.
8. Type ) and press Enter.
The completed function entry should look similar to the entry shown in the For-
mula Bar in Figure7-3. Ranges are separated by commas, and a grand sum is in
the cell where the function was typed.
When typing ranges into a formula, you can either type them or use the mouse to
drag over the range.
Excel has a special button, the AutoSum button, that makes it easier to use the
SUM function. The AutoSum button is on both the Home tab and the Formulas tab
of the Ribbon. The AutoSum feature works best with numbers that are in a vertical
or horizontal list. In a nutshell, AutoSum creates a range reference for the SUM
function to use. AutoSum makes its best guess about what the range should be.
Often, it gets it right— but sometimes, you have to help it along.
Using AutoSum is as easy as clicking and then pressing Enter. Figure7-4 shows
that the AutoSum button on the Ribbon has been clicked, and Excel, in its innite
wisdom, guessed correctly that the operation is to sum cells B6:B13. At this point,
the operation is incomplete. Pressing Enter nishes the formula.
FIGURE7-3:
Calculating a sum
of multiple
ranges.
CHAPTER 7 Using Basic Math Functions 125
You can click the check mark to the left of the formula, in the Formula Bar, to
complete the operation.
Follow these steps to use AutoSum:
1. Type some lists of numbers in a worksheet.
You can add labels to adjacent cells to identify the values, if desired.
2. Position the cursor in the cell where you want the results to appear.
3. Click the AutoSum button.
AutoSum has entered a suggested range in the SUM function.
4. Change the suggested range, if necessary, by typing it with the keyboard
or using the mouse to drag over a range of cells.
5. Press Enter or click the check mark on the Formula Bar to complete the
function.
It’s easy to use AutoSum to tally multiple ranges, such as those shown in
Figure7-3. Before ending the function with the Enter key or the check mark in the
Formula Bar, instead type a comma and then drag the mouse over another range.
Do this for as many ranges as you need to sum. Finally, nish the function by
pressing Enter or clicking the check mark in the Formula Bar.
By the way, the AutoSum button can do more than addition. If you click the down
arrow on the button, you have a choice of a few other key functions, such as Aver-
age (see Figure7-5).
FIGURE7-4:
Using AutoSum to
guess a range for
the SUM function.
126 PART 2 Doing the Math
Rounding Out Your Knowledge
Excel calculates answers to many decimal places. Unless you’re doing rocket sci-
ence, you probably don’t need such precise answers. Excel has a great set of func-
tions for rounding numbers so they’re usable for the rest of us.
Excel’s rounding functions are really helpful. The other day, my son had a couple
of his friends over. I ordered a large pizza for their lunch. That’s eight slices for
three hungry boys. How many slices does each boy get? Presto magic, I went over
to the computer where Excel was already running (okay, I am an Excel nut, after
all), and I typed this simple formula: =8/3.
Of course, Excel gave me the perfect answer. Each boy gets 2.66667 slices. Have
you ever tried to cut 66,667/100,000ths of a slice of pizza? Not easy! This is the
type of answer that rounding is used for. To tell you the truth, I did solve the pizza
problem a dierent way. I gave each boy two slices, and I ate the last two (pretty
good with mushrooms!).
Just plain old rounding
Easy to use, the ROUND function is the old tried-and-true method for rounding
o a number. It takes two arguments. One argument is the number to round (typ-
ically, this is a cell reference), and the other argument indicates how many deci-
mal places to round to.
The ROUND function rounds up or down, depending on the number being rounded.
When the value is less than the halfway point of the next signicant digit, the
number is rounded down. When the value is at or greater than the halfway point,
the number is rounded up, as follows:
FIGURE7-5:
Using AutoSum to
work with other
popular
functions.
CHAPTER 7 Using Basic Math Functions 127
»
10.4 rounds down to 10.
»
10.6 rounds up to 11.
»
10.5 also rounds up to 11.
Table7-1 shows some examples of the ROUND function.
Here’s how to use the ROUND function:
1. In a cell of your choice, type a number that has a decimal portion.
2. Position the cursor in the cell where you want the results to appear.
3. Type =ROUND( to begin the function entry.
4. Click the cell where you typed the number.
5. Type a comma (,).
6. Type a number to indicate how many decimal places to round to.
7. Type ) and press Enter.
TABLE7-1 Using the ROUND Function
Example of Function Result Comment
=ROUND(12.3456,1) 12.3 The second argument is 1. The result is rounded to a single
decimal place.
=ROUND(12.3456,2) 12.35 The second argument is 2. The result is rounded to two decimal
places. Note that the full decimal of .3456 becomes .35 because
the .0456 portion of the decimal value rounds to the closest
second-place decimal, which is .05.
=ROUND(12.3456,3) 12.346 The second argument is 3. The result is rounded to three decimal
places. Note that the full decimal or .3456 becomes .346 because
the .0056 portion of the decimal value rounds to the closest third-
place decimal, which is .006.
=ROUND(12.3456,4) 12.3456 The second argument is 4. There are four decimal places. No
rounding takes place.
=ROUND(12.3456,0) 12 When the second argument is 0, the number is rounded to the
nearest integer. Because 12.3456 is closer to 12 than to 13, the
number rounds to 12.
=ROUND(12.3456,-1) 10 When negative values are used in the second argument, the
rounding occurs on the left side of the decimal (the integer por-
tion). A second argument value of –1 tells the function to round to
the closest value of 10. In this example, that value is 10 because
12 is closer to 10 than to 20.
128 PART 2 Doing the Math
Rounding functions make the most sense when the rst argument is a cell refer-
ence, not an actual number. Think about it: If you know what a number should
appear as, you would just type the number. You would not need a function to
round it.
Rounding in one direction
Excel has a handful of functions that always round numbers up or always round
numbers down. That is, when Excel is rounding a number, the functions that
round down always give a result that is lower than the number itself. Functions
that round up, of course, always give a higher number. These functions are useful
when letting the good ol’ ROUND function determine which way to round just
won’t work.
A few of these rounding functions not only round in the desired direction but also
allow you to specify some additional ways of rounding. The EVEN and ODD func-
tions, for example, round to the closest even or odd number, respectively. The
CEILING and FLOOR functions let you round to a multiple. EVEN, ODD, CEILING,
and FLOOR are discussed later in this section.
Directional rounding, pure and simple
ROUNDUP and ROUNDDOWN are similar to the ROUND function. The rst argu-
ment to the function is the cell reference of the number to be rounded. The second
argument indicates the number of decimal places to round to. But unlike with
plain old ROUND, the rounding direction is not based on the halfway point of the
next signicant digit but on which function you use.
For example, =ROUND(4.22,1) returns 4.2, but =ROUNDUP(4.22,1) returns 4.3.
ROUNDDOWN, however, returns 4.2 because 4.2 is less than 4.22. Table7-2 shows
some examples of ROUNDUP and ROUNDDOWN.
Here’s how to use the ROUNDUP and ROUNDDOWN functions:
1. In a cell of your choice, type a number with a decimal portion.
2. Position the cursor in the cell where you want the results to appear.
3. Type =ROUNDUP( or =ROUNDDOWN( to begin the function entry.
4. Click the cell where you typed the number.
5. Type a comma (,).
6. Type a number to indicate how many decimal places to round to.
7. Type ) and press Enter.
CHAPTER 7 Using Basic Math Functions 129
Rounding to the multiple of choice
The FLOOR and CEILING functions take directional rounding to a new level. With
these functions, the second argument is a multiple to which to round to. What
does that mean?
Well, imagine this: You’re a human resources manager, and you need to prepare a
summary report of employee salaries. You don’t need the gures to be reported
down to the last penny— just rounded to the closest $250 multiple. Either FLOOR
or CEILING can do this. For this example, FLOOR can be used to round down to the
closest multiple of $250 that is less than the salary, or CEILING can be used to
round up to the next $250 multiple greater than the salary. Figure7-6 shows how
FLOOR and CEILING return rounded values.
TABLE7-2 Using the ROUNDUP and ROUNDDOWN Functions
Example of Function Result Comment
=ROUNDUP(150.255,0) 151 The second argument is 0. The result is rounded up to the next
higher integer, regardless of the fact that the decimal portion
would normally indicate the rounding would go to the next
lower integer.
=ROUNDUP(150.255,1) 150.3 The second argument is 1. The result is rounded to a single
decimal point. Note that the full decimal of .255 rounds up to .3.
This would also happen with the standard ROUND function.
=ROUNDUP(150.255,2) 150.26 The second argument is 2. The result is rounded to two decimal
places. Note that the full decimal of .255 becomes .26. This
would also happen with the standard ROUND function.
=ROUNDUP(150.255,3) 150.255 The second argument is 3, and there are three decimal places.
No rounding takes place.
=ROUNDDOWN(155.798,0) 155 The second argument is 0. The result is rounded down to the
integer portion of the number, regardless of the fact that the
decimal portion would normally indicate that the rounding
would go to the next higher integer.
=ROUNDDOWN(155.798,1) 155.7 The second argument is 1. The result is rounded to a single
decimal place. Note that the full decimal of .798 rounds down
to .7. The standard ROUND function would round the decimal
up to .8.
=ROUNDDOWN(155.798,2) 155.79 The second argument is 2. The result is rounded to two decimal
places. Note that the full decimal of .798 becomes .79. The
standard ROUND function would round the decimal up to .8.
=ROUNDDOWN(155.798,3) 155.798 The second argument is 3, and there are three decimal places.
No rounding takes place.
130 PART 2 Doing the Math
FLOOR and CEILING exceed the rounding ability of ROUND, ROUNDUP, and
ROUNDDOWN.These three functions can use the positioning of digit placeholders
in how they work. For example, =ROUND(B4,-3) tells the ROUND function to round
on the thousandth position. On the other hand, FLOOR and CEILING can round to
whatever specic multiple you set.
The FLOOR function rounds toward 0, returning the closest multiple of the second
argument that is lower than the number itself.
The CEILING function works in the opposite direction. CEILING will round its rst
argument, the number to be rounded, to the next multiple of the second number
that is in the direction away from 0.
Certainly, a few examples will make this clear! Table7-3 shows ways that FLOOR
and CEILING can be used.
FLOOR and CEILING can be used to round negative numbers. FLOOR rounds
toward 0, and CEILING rounds away from 0. FLOOR decreases a positive number
as it rounds it toward 0 and also decreases a negative number toward 0, although
in absolute terms, FLOOR actually increases the value of a negative number.
Weird, huh?
CEILING does the opposite. It increases a positive number away from 0 and also
increases a negative number away from 0, which in absolute terms means the
number is getting smaller.
For both the FLOOR and CEILING functions, the rst and second arguments must
match signs. Trying to apply a positive number with a negative multiple, or vice
versa, results in an error.
FIGURE7-6:
Using FLOOR or
CEILING to round
to a desired
multiple.
CHAPTER 7 Using Basic Math Functions 131
Here’s how to use the FLOOR and CEILING functions:
1. Type a number in any cell.
2. Position the cursor in the cell where you want the results to appear.
3. Type =FLOOR( or =CEILING( to begin the function entry.
4. Click the cell where you type the number.
5. Type a comma (,).
6. Type a number that is the next multiple you want to round the
number to.
For example, to get the oor value, at the ones place, make sure 1 is the
second argument. The rst argument should, of course, be a number larger
than 1 and should be a decimal value, like this: =Floor(19.77,1). This returns
19 as the oor, but hey— don’t hit the ceiling about it!
7. Type ) and press Enter.
Rounding to the next even or odd number
The EVEN and ODD functions round numbers away from 0. The EVEN function
rounds a number to the next highest even integer. ODD rounds a number to the
next highest odd integer. Table7-4 has examples of how these functions work.
TABLE7-3 Using FLOOR and CEILING for Sophisticated Rounding
Example of Function Result Comment
=FLOOR(30.17,0.05) 30.15 The second argument says to round to the next 0.05
multiple, in the direction of 0.
=FLOOR(30.17,0.1) 30.1 The second argument says to round to the next 0.1 multiple,
in the direction of 0.
=FLOOR(-30.17,-0.1) –30.1 The second argument says to round to the next 0.1 multiple,
in the direction of 0.
=CEILING(30.17,0.05) 30.2 The second argument says to round to the next 0.05
multiple, away from 0.
=CEILING(30.17,0.1) 30.2 The second argument says to round to the next 0.1 multiple,
away from 0.
=CEILING(-30.17,-0.1) –30.2 The second argument says to round to the next 0.1 multiple,
away from 0.
132 PART 2 Doing the Math
The EVEN function is helpful in calculations that depend on multiples of two. Say
you’re in charge of planning a school trip. You need to gure out how many bus
seats are needed for each class. A seat can t two children. When a class has an
odd number of children, you still have to count that last seat as taken, even though
only one child will sit there.
Say the class has 17 children. This formula tells you how many seats are needed:
=EVEN(17)/2. The EVEN function returns the number 18 (the next higher integer),
and that result is divided by 2 because 2 children t on each seat. The answer is 9
seats are needed for a class of 17.
Here’s how to use the EVEN and ODD functions:
1. Position the cursor in the cell where you want the results to appear.
2. Type =EVEN( or =ODD( to begin the function entry.
3. Click a cell where you typed a number, or type a number.
4. Type ) and press Enter.
TABLE7-4 Rounding to Even or Odd Integers
Example
of Function Result Comment
=EVEN(3) 4Rounds to the next even integer, moving away from 0.
=EVEN(4) 4Because 4 is an even number, no rounding takes place.
The number 4 itself is returned.
=EVEN(4.01) 6Rounds to the next even integer, moving away from 0.
=EVEN(-3.5) –4 Rounds to the next even integer, moving away from 0.
=ODD(3) 3Because 3 is an odd number, no rounding takes place.
The number 3 itself is returned.
=ODD(4) 5Rounds to the next odd integer, moving away from 0.
=ODD(5.01) 7Rounds to the next odd integer, moving away from 0.
=ODD(-3.5) –5 Rounds to the next odd integer, moving away from 0.
CHAPTER 7 Using Basic Math Functions 133
Leaving All Decimals Behind with INT
The INT function rounds a number down to the next lowest integer. The eect is
as if the decimal portion is just dropped, and often, INT is used to facilitate just
that: dropping the decimal.
INT comes in handy when all you need to know is the integer part of a number or
the integer part of a calculation’s result. For example, you may be estimating what
it will cost to build a piece of furniture. You have the prices for each type of raw
material, and you just want a ballpark total.
Figure7-7 shows a worksheet in which a project has been set up. Column A con-
tains item descriptions, and column B has the price for each item. Columns C and
D contain the parameters for the project. That is, column C contains the count of
each item needed, and column D has the amount to be spent for each item— that
is, the price per item multiplied by the number of items needed.
The sums to be spent are then summed into a project total. If you added the item
sums as they are— 83.88, 107.76, and 19.96— you get a total of $211.60. Instead,
the INT function is used to round the total to a ballpark gure of $211.
In cell D8, INT is applied to the total sum, like this:
=INT(SUM(D3:D5))
The INT function eectively drops the decimal portion, .60, and returns the inte-
ger part, 211. The project estimate is $211.
INT takes only the number as an argument. INT can work on positive or negative
values but works a little dierently with negative numbers. When working with
negative numbers, INT actually rounds down . . . When INT is working with posi-
tive numbers, the eect appears the same as just dropping the decimal. With neg-
ative numbers, the function drops the decimal portion and subtracts 1.
FIGURE7-7:
Using INT to drop
unnecessary
decimals.
134 PART 2 Doing the Math
With negative numbers, the function produces an integer that is farther away
from 0. Therefore, a number such as –25.25 becomes –26. Here are some
examples:
»
INT(25.25) returns 25.
»
INT(25.75) returns 25.
»
INT(-25.25) returns –26.
»
INT(-25.75) returns –26.
Here’s how to use the INT function:
1. In a cell of your choice, type a number that has a decimal portion.
2. Position the cursor in the cell where you want the results to appear.
3. Type =INT( to begin the function entry.
4. Click the cell where you typed the number.
5. Type ) to end the function and press Enter.
INT can also be used to return just the decimal part of a number. Subtracting the
integer portion of a number from its full value leaves just the decimal as the
answer. For example, =10.95-INT(10.95) is 0.95.
Leaving Some Decimals Behind
with TRUNC
The TRUNC function drops a part of a number. The function takes two arguments.
The rst argument is the number to be changed. The second argument indicates
how much of the number is to be dropped. A value of 2 for the second argument
says to leave 2 decimal places remaining. A value of 1 for the second argument
says to leave 1 decimal place remaining.
TRUNC does no rounding as it truncates numbers. Here are some examples:
»
=TRUNC(212.65,2) returns 212.65.
»
=TRUNC(212.65,1) returns 212.6.
»
=TRUNC(212.65,0) returns 212.
CHAPTER 7 Using Basic Math Functions 135
You can even use TRUNC to drop a portion of the number from the integer side. To
do this, you type negative values for the second argument, like this:
»
=TRUNC(212.65,-1) returns 210.
»
=TRUNC(212.65,-2) returns 200.
Assuming TRUNC has no decimal argument, then the INT and TRUNC functions
work exactly the same way for positive numbers. The only dierence is when
negative numbers are being changed. Then INT’s rounding produces a dierent
result than TRUNC’s truncation.
Looking for a Sign
Excel’s SIGN function tells you whether a number is positive or negative. The
SIGN function does not alter the number in any way but is used to nd out infor-
mation about the number.
SIGN does actually return a number, but it isn’t a variation of the number being
tested in the function. SIGN returns only three numbers:
»
1 if the number being tested is positive
»
–1 if the number being tested is negative
»
0 if the number being tested is 0
Consider these examples:
»
=SIGN(5) returns 1.
»
=SIGN(-5) returns –1.
»
=SIGN(0) returns 0.
Using SIGN in combination with other functions presents sophisticated ways of
working with your information. As an example, you may be tallying up a day’s
receipts from your store. You want to know the total value of sold merchandise
and the total value of returned merchandise. Sales are recorded as positive
amounts, and returns are recorded as negative amounts.
Figure7-8 shows a worksheet with these facts. Column A shows individual trans-
action amounts. Most amounts are sales and are positive. A few returns occurred
during the day, typed as negative amounts.
136 PART 2 Doing the Math
Just summing the whole transaction list would calculate the net revenue of the
day, but often, a business needs better information. Instead, two sums are calcu-
lated: the sum of sales and the sum of returns.
For each value in column A, there is a value in column B.The column B values are
the result of using the SIGN function. For example, cell B3 has this formula:
=SIGN(A3).
As shown in Figure7-8, values in column B equal 1 when the associated value in
column A is positive. Column B displays –1 when the associated value is negative.
This information is then used in a SUMIF function, which selectively sums infor-
mation from column A.
In cell B18 is this formula: =SUMIF(B3:B15,1,A3:A15).
In cell B19 is this formula: =ABS(SUMIF(B3:B15,-1,A3:A15)).
The SUMIF function is used to indicate a criterion to use in determining which
values to sum. For the sum of sales in cell B18, the presence of the value 1in col-
umn B determines which values to sum in column A.For the sum of returns in cell
B19, the presence of the value –1in column B determines which values to sum in
column A.
Also, the ABS function is used to present the number in cell B19 as a positive num-
ber. The answer in cell B19 is the sum of merchandise returns. You would say there
was $64.18 (not –$64.18) in returned merchandise, if you were asked.
FIGURE7-8:
Using SIGN to
sum amounts
correctly.
CHAPTER 7 Using Basic Math Functions 137
The SUMIF function is covered in Chapter8. The ABS function is covered next in
this chapter.
Here’s how to use the SIGN function:
1. Position the cursor in the cell where you want the results to appear.
2. Type =SIGN( to begin the function entry.
3. Click a cell where you typed a number, or type a number.
4. Type ) and press Enter.
Ignoring Signs
The ABS function returns the absolute value of a number. The absolute value is
always a positive. The absolute of a positive number is the number itself. The
absolute of a negative number is the number but with the sign changed to positive.
For example, =ABS(100) returns 100, as does =ABS(-100).
The ABS function is handy in a number of situations. For example, sometimes
imported data comes in as negative values, which need to be converted to their
positive equivalents. Or, when you’re working with cash ows, you can use the
ABS function to present cash ows as positive numbers.
A common use of the ABS function is to calculate the dierence between two
numbers when you don’t know which number has the greater value to begin with.
Say you need to calculate the dierence between scores for two contestants. Score
1 is in cell A5, and score 2 is in cell B5. The result goes in cell C5. The formula in
cell C5 would be =A5-B5.
Plugging in some numbers, assume that score 1 is 90 and score 2 is 75. The dier-
ence is 15. Okay, that’s a good answer. What happens when score 1 is 75 and score
2 is 90? The answer is –15. This answer is mathematically correct but not pre-
sented in a useful way. The dierence is still 15, not –15. When you use the ABS
function, the result is always returned as positive. Therefore, for this example, the
best formula coding is this: =ABS(A5-A6).
Now, whether score 1 is greater than score 2 or score 2 is greater than score 1, the
correct dierence is returned.
138 PART 2 Doing the Math
Here’s how to use the ABS function:
1. Position the cursor in the cell where you want the results to appear.
2. Type =ABS( to begin the function entry.
3. Click a cell where you typed a number, or type a number.
4. Type ) and press Enter.
CHAPTER 8 Advancing Your Math 139
Chapter8
Advancing Your Math
In this chapter, I show you some of the more advanced math functions. You
won’t use these functions every day, but they’re just the right thing when you
need them. Some of this will come back to you because you probably learned
most of this in school.
IN THIS CHAPTER
»
Calculating the circumference,
diameter, and area of a circle
»
Returning random numbers
»
Working with combinations and
permutations
»
Performing sophisticated
multiplication
»
Using the MOD function to test other
numerical values
»
Using the SUBTOTAL function for a
variety of arithmetic and statistical
totals
»
Using the SUMIF and SUMIFS
functions for selective summation
»
Getting an angle on trigonometry
functions
140 PART 2 Doing the Math
Using PI to Calculate Circumference and
Diameter
Pi is the ratio of a circle’s circumference to its diameter. A circle’s circumference is
its outer edge and is equal to the complete distance around the circle. A circle’s
diameter is the length of a straight line running from one side of the circle, through
the middle, and reaching the other side.
Dividing a circle’s circumference by its diameter returns a value of approximately
3.14159, known as pi. Pi is represented with the Greek letter pi and the symbol π.
Mathematicians have proved that pi is an irrational number— in other words, that
it has an innite number of decimal places. They have calculated the value of pi to
many thousands of decimal places, but you don’t need that level of precision in
most calculations. Many people use the value 3.14159 for pi, but the PI function in
Excel does a bit better than that. Excel returns a value of pi accurate to 15 digits—
that is 14 decimal places in addition to the integer 3. This function has no input
arguments. The function uses this syntax:
=PI()
In Excel, the PI function always returns 3.14159265358979, but initially, it may
look like some of the digits after the decimal point are missing. Change the for-
matting of the cell to display numbers with 14 decimal places to see the entire
number.
If you know the circumference of a circle, you can calculate its diameter with this
formula:
diameter = circumference ÷ π
If you know the diameter of a circle, you can calculate its circumference with this
formula:
circumference = diameter × π
If you know the diameter of a circle, you can calculate the area of the circle. A
component of this calculation is the radius, which equals one half of the diameter.
The formula is
area = (diameter × 0.5)2 × π
CHAPTER 8 Advancing Your Math 141
Generating and Using Random Numbers
Random numbers are, by denition, unpredictable. That is, given a series of ran-
dom numbers, you can’t predict the next number from what has come before.
Random numbers are quite useful for trying formulas and calculations. Suppose
that you’re creating a worksheet to perform various kinds of data analysis. You
may not have any real data yet, but you can generate random numbers to test the
formulas and charts in the worksheet.
For example, an actuary may want to test some calculations based on a distribu-
tion of people’s ages. Random numbers between 18 and 65 can be used for this
task. You don’t have to manually type xed values between 18 and 65, because
Excel can generate them automatically via the RAND function.
The all-purpose RAND function
The RAND function is simple; it takes no arguments and returns a decimal value
between 0 and 1. That is, RAND never actually returns 0 or 1; the value is always in
between these two numbers. The function is entered like this:
=RAND()
The RAND function returns values such as 0.136852731, 0.856104058, or
0.009277161. “Yikes!” you may be thinking. “How do these numbers help if you
need values between 18 and 65?” Actually, it’s easy with a little extra math.
There is a standard calculation for generating random numbers within a deter-
mined range. The calculation follows:
=RAND()*(high number–low number)+low number
Using 18 and 65 as a desired range of numbers, the formula looks like
=RAND()*(65-18)+18. Some sample values returned with this formula follow:
51.71777896
27.20727871
24.61657068
55.27298686
49.93632709
43.60069745
142 PART 2 Doing the Math
Almost usable! But what about the long decimal portions of these numbers? Some
people lie about their ages, but I’ve never heard someone say they’re 27.2 years old!
All that is needed now for this 18-to-65 age example is to include the INT or
ROUND function. INT simply discards the decimal portion of a number. ROUND
allows control of how to handle the decimal portion.
The syntax for using the INT function with the RAND function follows:
=INT((high number–low number+1)*RAND()+low number)
The syntax for using the ROUND function with the RAND function follows:
=ROUND(RAND()*(high number-low number)+low number,0)
Try it yourself! Here’s how to use RAND and INT together:
1. Position the pointer in the cell where you want the results displayed.
2. Type =INT(( to begin the formula.
3. Click the cell that has the highest number to be used, or type such a
value.
4. Type a hyphen (-).
5. Click the cell that has the lowest number to be used, or type such a value.
6. Type +1)*RAND()+.
7. Again, click the cell that has the lowest number to be used, or type the
value.
8. Type ) and press Enter.
A random number, somewhere in the range between the low and high number, is
returned.
Table8-1 shows how returned random numbers can be altered with the INT and
ROUND functions.
Table8-1 points out how the INT and ROUND functions return dierent numbers.
For example, 51.71777896 is more accurately rounded to 52. Bear in mind that the
second argument in the ROUND function, 0in this case, has an eect on how the
rounding works. A 0 tells the ROUND function to round the number to the nearest
integer, up or down to whichever integer is closest to the number.
CHAPTER 8 Advancing Your Math 143
Random values are volatile. Each time a worksheet is recalculated, the random
values change. You can prevent this behavior by typing the formula directly in the
Formula Bar, pressing the F9 key, and then pressing Enter.
A last but not insignicant note about using the RAND function: It is subject to the
recalculation feature built into worksheets. In other words, each time the work-
sheet calculates, the RAND function is rerun and returns a new random number.
The calculation setting in your worksheet is probably set to automatic. You can
check this by looking at the Formulas tab of the Excel Options dialog box.
Figure8-1 shows the calculation setting. On a setting of Automatic, the worksheet
recalculates with every action. The random generated numbers keep changing,
which can become quite annoying if this is not what you intended to have happen.
However, I bet you did want the number to change; otherwise, why use something
“random” in the rst place?
Luckily, you can generate a random number but have it remain xed regardless of
the calculation setting. The method is to type the RAND function, along with any
other parts of a larger formula, directly in the Formula Bar. After you type your
formula, press the F9 key and then press Enter. This tells Excel to calculate the
formula and type the returned random number as a xed number instead
of a formula. If you press Enter or nish the entry in some way without pressing
the F9 key, you have to type it again.
Precise randomness with RANDBETWEEN
Using the RAND function returns a value between 0 and 1, and when you use it
with other functions, such as ROUND, you can get a random number within a
range that you specify. If you just need a quick way to get an integer (no decimal
portion!) within a given range, use RANDBETWEEN.
TABLE8-1 Using INT and ROUND to Process Random Values
Value Value Returned with INT Value Returned with ROUND
51.71777896 51 52
27.20727871 27 27
24.61657068 24 25
55.27298686 55 55
49.93632709 49 50
43.60069745 43 44
144 PART 2 Doing the Math
The RANDBETWEEN function takes two arguments: the low and high numbers of
the desired range. It works only with integers. You can put real numbers in the
range, but the result will still be an integer.
To use RANDBETWEEN, follow these steps:
1. Position the pointer in the cell where you want the results displayed.
2. Type =RANDBETWEEN( to begin the formula.
3. Click the cell that has the low number of the desired range, or type such
a value.
4. Type a comma (,).
5. Click the cell that has the highest number of the desired range, or type
such a value.
6. Type ) and press Enter.
For example, =RANDBETWEEN(10,20) returns a random integer between 10 and 20.
FIGURE8-1:
Setting worksheet
calculation
options.
CHAPTER 8 Advancing Your Math 145
Ordering Items
Remember the Beatles? John, Paul, George, and Ringo? If you’re a drummer, you
may think of the Beatles as Ringo, John, Paul, and George. The order of items in a
list is known as a permutation. The more items in a list, the more possible permu-
tations exist.
Excel provides the PERMUT function for calculating the number of permutations.
It takes two arguments: the total number of items to choose among and the num-
ber of items to be used in determining the permutations. The function returns a
single whole number. The syntax of the function follows:
=PERMUT(total number of items,number of items to use)
Use permutations when the order of items is important.
The total number of items must be the same as or greater than the number of
items to use; otherwise, an error is generated.
You may be confused about why the function takes two arguments. On the surface,
it seems that the rst argument is sucient. Well, not quite. (Getting back to the
Beatles, anyone have a copy of Abbey Road I can borrow?) If we plug in 4 as the
number for both arguments
=PERMUT(4,4)
Twenty-four permutations are returned:
»
John Paul George Ringo
»
John Paul Ringo George
»
John George Paul Ringo
»
John George Ringo Paul
»
John Ringo Paul George
»
John Ringo George Paul
»
Paul John George Ringo
»
Paul John Ringo George
»
Paul George John Ringo
»
Paul George Ringo John
»
Paul Ringo John George
146 PART 2 Doing the Math
»
Paul Ringo George John
»
George John Paul Ringo
»
George John Ringo Paul
»
George Paul John Ringo
»
George Paul Ringo John
»
George Ringo John Paul
»
George Ringo Paul John
»
Ringo John Paul George
»
Ringo John George Paul
»
Ringo Paul John George
»
Ringo Paul George John
»
Ringo George John Paul
»
Ringo George Paul John
Altering the function to use 2 items at a time from the total of 4 items —
PERMUT(4,2)— returns just 12 permutations:
»
John Paul
»
John George
»
John Ringo
»
Paul John
»
Paul George
»
Paul Ringo
»
George John
»
George Paul
»
George Ringo
»
Ringo John
»
Ringo Paul
»
Ringo George
Just for contrast, using the number 2 for both arguments — PERMUT(2,2) —
returns just two items! When using PERMUT, make sure you’ve selected the
CHAPTER 8 Advancing Your Math 147
correct numbers for the two arguments; otherwise, you’ll end up with an incorrect
result and may not be aware of the mistake. The PERMUT function simply returns
a number. The validity of the number is in your hands.
Combining
Combinations are similar to permutations but with a distinct dierence. The order
of items is intrinsic to permutations. Combinations, however, are groupings of
items in which the order doesn’t matter. For example, “John Paul George Ringo”
and “Ringo George Paul John” are two distinct permutations but identical
combinations.
Combinations are groupings of items, regardless of the order of the items.
The syntax of the function follows:
=COMBIN(total number of items,number of items to use)
The rst argument is the total number of items to choose among, and the second
argument is the number of items to be used in determining the combinations. The
function returns a single whole number. The arguments for the COMBIN function
are the same as those for the PERMUT function. The rst argument must be equal
to or greater than the second argument.
Plugging in the number 4 for both arguments— COMBIN(4,4)— returns 1. Yes,
there is just one combination of four items selected from a total of four items!
Using the Beatles once again, just one combination of the four musicians exists,
because the order of names doesn’t matter.
Selecting to use two items from a total of four — COMBIN(4,2) — returns 6.
Selecting two items out of two— COMBIN(2,2)— returns 1. In fact, whenever the
two arguments to the COMBIN function are the same, the result is always 1.
Raising Numbers to New Heights
There is an old tale about a king who loved chess so much, he decided to reward
the inventor of chess by granting any request he had. The inventor asked for a
grain of wheat for the rst square of the chessboard on Monday, two grains for the
second square on Tuesday, four for the third square on Wednesday, eight for the
148 PART 2 Doing the Math
fourth square on Thursday, and so on, each day doubling the amount until the
64th square was lled with wheat. The king thought this was a silly request. The
inventor could have asked for riches!
What happened was that the kingdom quickly ran out of wheat. By the 15th day,
the number equaled 16,384. By the 20th day, the number was 524,288. On the
64th day, the number would have been an astonishing 9,223,372,036,854,780,000,
but the kingdom had run out of wheat at least a couple of weeks earlier!
This “powerful” math is literally known as raising a number to a power. The
power, in this case, means how many times a number is to be multiplied by itself.
The notation is typically a superscript (23 for example). Another common way of
noting the use of a power is with the caret symbol: 2^3. The verbiage for this is two
to the third power, or two to the power of three.
In the chess example, 2 is raised to a higher power each day. Table8-2 shows the
rst 10 days.
The concept is easy enough. Each time the power is incremented by 1, the result
doubles. Note that the rst entry raises 2 to the 0 power. Isn’t that strange? Well,
not really. Any number raised to the 0 power equals 1. Also note that any number
raised to the power of 1 equals the number itself.
TABLE8-2 The Power of Raising Numbers to a Power
Day Power That 2 Is Raised To Power Notation Basic Math Notation Result
1 0 201 1
2 1 212 2
3 2 222 × 2 4
4 3 232 × 2 × 2 8
5 4 242 × 2 × 2 ×216
6 5 252 × 2 × 2 × 2 × 2 32
7 6 262 × 2 × 2 × 2 × 2 × 2 64
8 7 272 × 2 × 2 × 2 × 2 × 2 × 2 128
9 8 282 × 2 × 2 × 2 × 2 × 2 × 2 × 2 256
10 9 292 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 512
CHAPTER 8 Advancing Your Math 149
Excel provides the POWER function, whose syntax follows:
=POWER(number,power)
Both the number and power arguments can be integer or real numbers, and nega-
tive numbers are allowed.
In a worksheet, either the POWER function or the caret can be used. For example,
in a cell you can type =POWER(4,3), or =4^3. The result is the same either way.
You insert the caret by holding Shift and pressing the number 6 key on the
keyboard.
Multiplying Multiple Numbers
The PRODUCT function is useful for multiplying up to 255 numbers at a time. The
syntax follows:
=PRODUCT(number1,number2,...)
Cell references can be included in the argument list, as well as actual numbers,
and of course, they can be mixed. Therefore, all these variations work:
=PRODUCT(A2,B15,C20)
=PRODUCT(5,8,22)
=PRODUCT(A10,5,B9)
In fact, you can use arrays of numbers as the arguments. In this case, the notation
looks like this:
=PRODUCT(B85:B88,C85:C88,D86:D88)
Here’s how to use the PRODUCT function:
1. Type some values in a worksheet.
You can include many values, going down columns or across in rows.
2. Position the pointer in the cell where you want the results displayed.
3. Type =PRODUCT( to begin the function.
4. Click a cell that has a number.
Alternatively, you can hold down the left mouse button and drag the pointer
over a range of cells with numbers.
150 PART 2 Doing the Math
5. Type a comma (,).
6. Repeat steps 4 and 5 up to 254 times.
7. Type ) and press Enter.
The result you see is calculated by multiplying all the numbers you selected. Your
ngers would probably hurt if you had done this on a calculator.
Figure8-2 shows this on a worksheet. Cell C10 shows the result of multiplying 12
numbers, although only three arguments, as ranges, have been used in the
function.
Using What Remains with the MOD
Function
The MOD function returns the remainder from an integer division operation. This
remainder is called the modulus, hence the function’s name. The function has two
arguments: the number being divided and the number being used to divide the
rst argument. The second argument is the divisor. The syntax follows:
=MOD(number,divisor)
These are examples of the MOD function:
»
=MOD(12,6) returns 0.
»
=MOD(14,5) returns 4.
»
=MOD(27,7) returns 6.
»
=MOD(25,10) returns 5.
FIGURE8-2:
Putting the
PRODUCT
function to work.
CHAPTER 8 Advancing Your Math 151
»
=MOD(25,-10) returns –5.
»
=MOD(15.675,8.25) returns 7.425.
The returned value is always the same sign as the divisor.
You can use MOD to tell whether a number is odd or even. If you simply use a
number 2 as the second argument, the returned value will be 0 if the rst argu-
ment is an even number, and 1 if it is not.
But what’s so great about that? You can just look at a number and tell whether it’s
odd or even. The power of the MOD function is apparent when you’re testing a
reference or formula, such as =MOD(D12-G15,2). In a complex worksheet with
many formulas, you may not be able to tell when a cell will contain an odd or even
number.
Taking this a step further, the MOD function can be used to identify cells in a
worksheet that are multiples of the divisor. Figure8-3 shows how this works.
Row 1 of the worksheet in Figure8-3 shows examples of the formulas that are
typed in the successive rows of columns B and C, starting from the second row.
Column A contains numbers that will be tested with the MOD function. If you’re
looking for multiples of 4, the MOD function has 4 as the divisor, and when a value
is a multiple of 4, MOD returns 0. This is evident when you compare the numbers
in column A with the returned values in column B.
FIGURE8-3:
Using MOD to
nd specic
values.
152 PART 2 Doing the Math
The same approach is used in column C, only here the divisor is 10, so multiples of
10 are being tested for in column A.Where a 0 appears in column C, the associated
number in column A is a multiple of 10.
In this way, you can use the MOD function to nd meaningful values in a
worksheet.
The ISODD and ISEVEN functions can also be used to test odd and even.
Summing Things Up
Aha! Just when you think you know how to sum up numbers (really, haven’t you
been doing this since your early school years?), I present a fancy-footwork sum-
ming that makes you think twice before going for that quick total.
The functions here are very cool— very “in” with the math crowd. To be a true
Excel guru, try the SUBTOTAL, SUMPRODUCT, SUMIF, and SUMIFS functions
shown here, and then strut your stu around the oce!
Using SUBTOTAL
The SUBTOTAL function is very exible. It doesn’t perform just one calculation; it
can do any of 11 calculations depending on what you need. What’s more, SUBTOTAL
can perform these calculations on up to 255 ranges of numbers. This gives you the
ability to get exactly the type of summary you need without creating a complex set
of formulas. The syntax of the function follows:
=SUBTOTAL(function number,range1,range2,...)
The rst argument determines which calculation is performed. It can be any of the
values shown in Table8-3. The remaining arguments identify the ranges contain-
ing the numbers to be used in the calculation.
Figure8-4 shows examples of using the SUBTOTAL function. Raw data values are
listed in column A.The results of using the function in a few variations are listed
in column C. Column E displays the actual function entries that returned the
respective results in column C.
Using named ranges with the SUBTOTAL function is useful. For example,
=SUBTOTAL(1,October_Sales,November_Sales,December_sales) makes for an
easy way to calculate the average sale of the fourth quarter.
CHAPTER 8 Advancing Your Math 153
TABLE8-3 Argument Values for the SUBTOTAL Function
Function Number
for First Argument Function Description
1AVERAGE Returns the average value of a group of numbers
2COUNT Returns the count of cells that contain numbers
and also numbers within the list of arguments
3COUNTA Returns the count of cells that are not empty and
only nonempty values within the list of arguments
4MAX Returns the maximum value in a group of
numbers
5MIN Returns the minimum value in a group of
numbers
6PRODUCT Returns the product of a group of numbers
7STDEV.S Returns the standard deviation from a sample of
values
8STDEV.P Returns the standard deviation from an entire
population, including text and logical values
9SUM Returns the sum of a group of numbers
10 VAR.S Returns variance based on a sample
11 VAR.P Returns variance based on an entire population
FIGURE8-4:
Working with the
SUBTOTAL
function.
154 PART 2 Doing the Math
A second set of numbers can be used for the Function Number (the rst argument
in the SUBTOTAL function). These numbers start with 101 and are the same func-
tions as shown in Table 8-3. For example, 101 is AVERAGE, 102 is COUNT, and
so on.
The 1 through 11 Function Numbers consider all values in a range. The 101 through
111 Function Numbers tell the function to ignore values that are in hidden rows or
columns. Figure8-5 shows SUBTOTAL in use with both Function Number sys-
tems. Comparing Figure8-5 to Figure8-4, you can see that row 2 has been set to
hidden. In Figure8-5, the values in column B are calculated using the same Func-
tion Numbers as in Figure8-4; column G shows SUBTOTAL using the Function
Numbers that start with 101. For example, cell B3 still shows the average of the
numbers in the range A1:A6 as equal to 14. The result in cell G3 shows the average
of A1:A6 equal to 15.2. The value of 8in cell A2 is not used because it is hidden.
Using SUMPRODUCT
The SUMPRODUCT function provides a sophisticated way to add various
products— across ranges of values. It doesn’t just add the products of separate
ranges; it produces products of the values positioned in the same place in each
range and then sums up those products. The syntax of the function follows:
=SUMPRODUCT(Range1,Range2,...)
The arguments to SUMPRODUCT must be ranges, although a range can be a single
cell or value. What is required is that all the ranges be the same size, both rows
and columns. Up to 255 ranges are allowed, and at least 2 are required.
FIGURE8-5:
Getting
SUBTOTAL to
ignore hidden
values.
CHAPTER 8 Advancing Your Math 155
SUMPRODUCT works by rst multiplying elements, by position, across the ranges
and then adding all the results. To see how this works, take a look at the three
ranges of values in Figure8-6. I put letters in the ranges instead of numbers to
make this easier to explain.
Suppose that you typed the following formula in the worksheet:
=SUMPRODUCT(B2:C4,E2:F4,H2:I4)
The result would be calculated by the following steps:
1. Multiplying A times H times N and saving the result
2. Multiplying D times K times Q and saving the result
3. Multiplying B times I times O and saving the result
4. Multiplying E times L times R and saving the result
5. Multiplying C times J times P and saving the result
6. Multiplying F times M times S and saving the result
7. Adding all six results to get the nal answer
Be careful when you’re using the SUMPRODUCT function. It’s easy to mistakenly
assume that the function adds products of individual ranges. It doesn’t.
SUMPRODUCT returns the sums of products across positional elements.
As confusing as SUMPRODUCT seems, it actually has a sophisticated use. Imagine
that you have a list of units sold by product and another list of the products’
prices. You need to know total sales (that is, the sum of the amounts), in which an
amount is units sold times the unit price.
In the old days of spreadsheets, you would use an additional column to rst mul-
tiply each unit sold gure by its price. Then you would sum those intermediate
values. Now, with SUMPRODUCT, the drudgery is over. The single use of
FIGURE8-6:
Following the
steps used by
SUMPRODUCT.
156 PART 2 Doing the Math
SUMPRODUCT gets the nal answer in one step. Figure8-7 shows how one cell
contains the needed grand total. No intermediate steps are necessary.
Using SUMIF and SUMIFS
SUMIF is one of the real gemstones of Excel functions. It calculates the sum of a
range of values, including only those values that meet a specied criterion.
Suppose that you use a worksheet to keep track of all your food-store purchases.
For each shopping trip, you put the date in column A, the amount in column B,
and the name of the store in column C.You can use the SUMIF function to tell
Excel to add all the values in column B only where column C contains Great
Grocery. That’s it. SUMIF gives you the answer. Neat!
Figure 8-8 shows this example. The date of purchase, place of purchase, and
amount spent are listed in three columns. SUMIF calculates the sum of purchases
at Great Grocery. Here is how the function is written for the example:
=SUMIF(C3:C15,"Great Grocery",B3:B15)
Here are a couple of important points about the SUMIF function:
»
The second argument can accommodate several variations of expressions,
such as including greater than (>) or less than (<) signs or other operators. For
example, if a column has regions such as North, South, East, and West, the
criteria could be <>North, which would return the sum of rows that are not for
the North region.
»
Unpredictable results occur if the ranges in the rst and third arguments do
not match in size.
FIGURE8-7:
Being productive
with
SUMPRODUCT.
CHAPTER 8 Advancing Your Math 157
Try it yourself! Here’s how to use the SUMIF function:
1. Type two ranges of data in a worksheet.
At least one should contain numerical data. Make sure both ranges are the
same size.
2. Position the pointer in the cell where you want the results displayed.
3. Type =SUMIF( to begin the function.
4. Hold down the left mouse button and drag the pointer over one of the
ranges.
This is the range that can be other than numerical data.
5. Type a comma (,).
6. Click one of the cells in the rst range.
This is the criterion.
7. Type a comma (,).
8. Hold down the left mouse button and drag the pointer over the second
range.
This is the range that must contain numerical data.
9. Type ) and press Enter.
The result you see is a sum of the numeric values where the items in the rst
range matched the selected criteria.
FIGURE8-8:
Using SUMIF for
targeted tallying.
158 PART 2 Doing the Math
The example in Figure8-8 sums values when the store is Great Grocery but does
not use the date in the calculation. What if you need to know how much was spent
at Great Grocery in April only? Excel provides a function for this, of course:
SUMIFS.
SUMIFS lets you apply multiple “if” conditions to a sum. The format of SUMIFS is
a bit dierent from that of SUMIF.SUMIFS uses this structure:
=SUMIFS(range to be summed,criteria range 1,criteria 1,criteria
range 2,criteria 2)
The structure requires the range of numerical values to be typed rst, followed by
pairs of criteria ranges and the criteria itself. In Figure8-9, the formula is
=SUMIFS(B3:B15,A3:A15,"<5/1/2020",C3:C15,"Great Grocery")
The function uses B3:B15 as the source of values to sum. A3:A15 is the rst criteria
range, and <5/1/2020 is the criteria. This tells the function to look for any date
that is earlier than May 1, 2020 (which lters the dates to just April). This is fol-
lowed by a second criteria range and value: In C3:C15, look just for Great Grocery.
The nal sum of $84.24 adds just three numbers— 15.04, 42.25, and 26.95—
because these are the only values in April for Great Grocery.
FIGURE8-9:
Using SUMIFS to
get a multiple
ltered sum.
CHAPTER 8 Advancing Your Math 159
Getting an Angle on Trigonometry
Did you think Excel was not up to snu to provide some tricks for trigonometry?
Then think again. Who can resist playing around with such exciting things like
cosines and tangents? All right, I admit this is not for everyone, but here are the
trig functions nonetheless. Besides, even if the concepts are dicult, you can
always throw around the terms at a party and be recognized as the brainiest per-
son there.
Three basic trigonometry functions
The sine, cosine, and tangent of an angle are likely the most used values in trigo-
nometry calculations. They provide answers about the relationships of a triangle’s
angles to the sides of the triangle. (See how I boiled down the bulk of trigonometry
into a single sentence!)
Figure8-10 shows a handful of angles in column A and their corresponding sine,
cosine, and tangent values in columns B, C, and D, respectively.
The SIN, COS, and TAN functions take just the single argument of a number (the
angle) and return the converted values. The functions look like this if the angles
are in radians:
=SIN(angle)
=COS(angle)
=TAN(angle)
FIGURE8-10:
Using SIN, COS,
and TAN
functions.
160 PART 2 Doing the Math
If the angles are in degrees, they need to be converted to radians by the RADIANS
function. In this case, you would use these:
=SIN(RADIANS(angle))
=COS(RADIANS(angle))
=TAN(RADIANS(angle))
Which leads you to... .
Degrees and radians
An angle can be expressed in degrees or radians. A degree is more common to us
non–rocket scientists. Most everyone knows that there are 360 degrees in a circle,
that a right angle is 90 degrees, and even that “doing a 180” means turning com-
pletely around and going the other way.
One radian = 180 ÷ π degrees, and one degree = π ÷ 180 radians. (All this talk about
pi is making me hungry!) For lowdown and quick conversion: 1 radian = 57.3
degrees.
Pi is approximately equal to 3.14159. See the beginning of this chapter for a forkful
of pi.
Excel provides the RADIANS and DEGREES functions to convert a number from
radians to degrees or vice versa. I think the real reason Excel did this was to keep
pi out of the picture so you would concentrate on work and not dessert.
The functions are the single argument type:
=RADIANS(angle in degrees)
=DEGREES(angle in radians)
Using some numbers, you can see that 90 degrees = 1.5707963267949 radians and
so 1.5707963267949 radians must equal 90 degrees. And it does.
3
Solving with
Statistics
IN THIS PART ...
Get familiar with basic statistics.
See how estimating works.
Make predictions and nd out what’s probable.
CHAPTER 9 Throwing Statistics aCurve 163
Chapter9
Throwing Statistics
aCurve
Just pick up the newspaper, or turn on the television or the radio. We’re bom-
barded with interesting facts and gures that are the result of statistical work:
There is a 60 percent chance of rain, the Dow Jones Industrial Average gained
2.8 percent, the Yankees are favored over the Red Sox 4-3, and so on.
Statistics are used to tell us facts about the world around us. Statistics are also
used to tell us lies about our world. Statistics can be used to confuse or obscure
information. Imagine that you try a new candy bar and you like it. Well, then you
can boast that 100 percent of the people who tried it liked it!
Sometimes, statistics produce odd conclusions— to say the least! Imagine this:
Bill Gates helps at a homeless shelter. The average wealth of the 40 or so people in
the room is $1 billion. Why? Because Bill’s worth is counted in the average, thereby
skewing the average past the point of making sense. How about this? You hear on
the news that the price of gasoline dropped 6 percent. Hurray! Let’s go on a trip.
But what is that 6 percent decrease based on? Is it a comparison with last week’s
price, last month’s price, or last year’s price? Perhaps the price of gasoline dropped
IN THIS CHAPTER
»
Understanding key terms used in
statistics
»
Testing for central tendencies in a
data sample
»
Analyzing deviation in a data sample
»
Looking for similarities in two data
samples
»
Analyzing by bins and percentiles
»
Counting items in a data sample
164 PART 3 Solving with Statistics
6 percent compared with last month. But prices are still 20 percent higher than
last year. Is this good news?
Statistics are traditionally divided into two types. Descriptive statistics, covered in
this chapter, help you summarize and understand data. Inferential statistics, cov-
ered in Chapter10, are used to draw conclusions about data comparisons.
Getting Stuck in the Middle with AVERAGE,
MEDIAN, and MODE
Are you of average height? Do you earn an average income? Are your children get-
ting above-average grades? There is more than a single way to determine the
middle value from a group of values. There are three common statistical functions
that describe the center value from a population of values. These are the mean, the
median, and the mode.
The term population refers to all possible measurements or data points, whereas
the term sample refers to the measurements or data points that you actually have.
For example, if you are conducting a survey of registered voters in New Jersey, the
population is all registered voters in the state, and the sample is those voters who
actually took the survey.
Technically, the term average refers to the mean value, but in common language,
average can also be used to mean the median or the mode instead of the mean.
This leads to all sorts of wonderful claims by advertisers and anyone else who
wants to make a point.
It’s important to understand the dierence between these terms:
»
Mean: The mean is a calculated value. It’s the result of summing the values in
a list or set of values and then dividing the sum by the number of values. For
example, the average of the numbers 1, 2, and 3 equals 2. This is calculated as
(1 + 2 + 3) ÷ 3 or 6 ÷ 3.
»
Median: The median is the middle value in a sorted list of values. If there is an
odd number of items in the list, the median is the actual middle value. In lists
with an even number of items, there is no actual middle value. In this case, the
median is the mean of the two values in the middle. For example, the median
of 1, 2, 3, 4, 5 is 3 because the middle value is 3. The median of 1, 2, 3, 4, 5, 6 is
3.5 because the mean of the two middle values, 3 and 4, is 3.5.
CHAPTER 9 Throwing Statistics aCurve 165
»
Mode: The mode is the value that has the highest occurrence in a list of
values. It may not exist! In the list of values 1, 2, 3, 4, there is no mode because
each number is present the same number of times. In the list of values 1, 2, 2,
3, 4, the mode is 2 because 2 is used twice and the other numbers are used
once.
The mean, median, and mode are sometimes called measures of central tendency
because they serve to summarize a data sample in a single statistic.
Let’s get started! These steps create three results in your worksheet, using the
AVERAGE, MEDIAN, and MODE functions:
1. Type a list of numerical values.
Any mix of numbers will do.
2. Position the cursor in the cell where you want the mean to appear.
3. Type =AVERAGE( to start the function.
4. Drag the pointer over the list or type the address of the range.
5. Type ) to end the AVERAGE function.
6. Position the cursor in the cell where you want the median to appear.
7. Type =MEDIAN( to start the function.
8. Drag the pointer over the list or type the address of the range.
9. Type ) to end the MEDIAN function.
10. Position the cursor in the cell where you want the mode to appear.
11. Type =MODE.SNGL( to start the function.
12. Drag the pointer over the list or type the address of the range.
13. Type ) to end the MODE function.
Depending on the numbers you typed, the three results may be the same (very
unlikely!), about the same, or quite dierent. The MODE function will have
returned #N/A if there were no repeating values in your data.
The mean is calculated by the AVERAGE function.
Imagine this: Three people use a new toothpaste for 6 months, and then all go to
the dentist. Two have no cavities. Hey, this toothpaste is great! The third person
has three cavities. Uh-oh!
166 PART 3 Solving with Statistics
Person Cavities
A 0
B 0
C 3
The average number of cavities for this group is 1— that is, if you’re using the
mean as the average. This doesn’t sound like a good toothpaste if, on average, each
person who used it got a cavity! On the other hand, both the median and the mode
equal 0. The median equals 0 because that’s the middle value in the sorted list.
The mode equals 0 because that’s the highest occurring value. As you can see,
statistics prove that the new toothpaste gives 0 cavities, on average— sort of.
Look at another example. Figure9-1 shows the results of a midterm test for a
hypothetical class. The mean, median, and mode are shown for the distribution of
grades.
As almost always happens, the mean, the median, and the mode each return a dif-
ferent number. Strictly speaking, we should say that the average grade is 86.72,
the mean value. But if the teacher or the school wants to make the impact on stu-
dents look better, they could point out that the most frequently occurring score is
94. This is the mode, and sure enough, three students did receive a 94. But is this
the best representation of the overall results? Probably not.
FIGURE9-1:
Dening central
tendencies in a
list of grades.
CHAPTER 9 Throwing Statistics aCurve 167
Working with the functions that return these measures of central tendencies—
AVERAGE, MEDIAN, and MODE— can make for interesting and sometimes mis-
leading results. Here is one more example of how these three functions can give
widely dierent results for the same data. Here is data for six customers and what
they spent with a company last year:
Customer Total Amount Spent Last Year
A$300
B$90
C$2,600
D$850
E$28,400
F$300
The mean (using the AVERAGE function) is $5,423.33. The median is $575, and the
mode is $300. These three amounts aren’t even close! Which one best represents
the typical amount that a customer spent last year?
The issue with this set of data is that one value— $28,400— is so much larger
than the other values that it skews the mean. You may be led to believe that each
customer spent about $5,423. But looking at the real values, only one customer
spent a lot of money, relatively speaking. Customers A, B, C, D, and F spent
nowhere near $5,423.33, so how can that “average” apply to them?
Figure9-2 shows a situation in which one value is way out of league with the
rest — sometimes called an outlier, which makes the average not too useful.
Figure9-2 also shows how much the mean changes if the one spendthrift cus-
tomer is left out, but if you leave out any other customer, there is very little change
in the mean.
In Scenario 2, Customer E is left out. The mean and the median are much closer
together— $968 and $850, respectively. Either amount reasonably represents the
mid value of what customers spent last year.
But can you just drop a customer like that (not to mention the biggest customer)?
Yikes! Instead, you can consider a couple of creative averaging solutions. Either
use the median or use a weighted average (a calculation of the mean in which the
relevance of each value is taken into account). Figure9-3 shows the result of each
approach.
168 PART 3 Solving with Statistics
Scenario 1 shows the mean and the median for the set of customer amounts. Here,
using the median is a better representation of the central tendency of the group.
When reporting results based on an atypical calculation, it’s good practice to add
a footnote that explains how the answer was determined. If you were to report
that the “average” expenditure was $925, a note should explain this is the median,
not the mean.
FIGURE9-2:
Deciding what to
do with an
unusual value.
FIGURE9-3:
Calculating a
creative mean.
CHAPTER 9 Throwing Statistics aCurve 169
Scenario 2in Figure9-3 is a little more complex. This involves making a weighted
average, which is used to let individual values be more or less inuential in the
calculation of a mean. This is just what you need! Customer E needs to be less
inuential.
Weighted averages are the result of applying a weighting factor to each value that
is used in calculating the mean. In this example, all the customers are given a
weight factor of 18 except Customer E, who has a weight factor of 10. All customers
except Customer E have been given increased weight, and Customer E has been
given decreased weight because their sales value is so dierent from all the others.
When weights are applied in an average, the sum of the weights must equal 100.
If no weighting factor is applied, each customer eectively has a weight of
16.667— the number of customers divided into 100. Applying a weight of 10 to
Customer E and 18 to all the other customers keeps the sum of the weights at 100:
18 × 5 + 10. The values of 18 and 10 have been subjectively chosen. When you use
weighting factors to calculate a weighted average, you must make that fact known
when you present the results.
The mean in Scenario 2 is $3,711. This gure is still way above the median or even
the mean of just the ve customers without Customer E (refer to Figure 9-2).
Even so, it’s less than the unweighted mean shown in Scenario 1 and is probably a
more accurate reection of the data.
By the way, the mean in Scenario 2 is not calculated with the AVERAGE function,
which cannot handle weighted means. Instead, the SUMPRODUCT function is
used. The actual formula in cell F18 looks like this:
=SUMPRODUCT(F9:F14,G9:G14)/SUM(G9:G14)
The amount that each customer spent last year is multiplied by that customer’s
weight, and a sum of those products is calculated with SUMPRODUCT.Finally, the
sum of the products is divided by the sum of the weights.
Turn to Chapter8 for more about the SUMPRODUCT function.
Deviating from the Middle
Life is full of variety! Calculating the mean for a group will not reect that variety.
Suppose that you are doing a survey of salaries for dierent occupations and that
occupation A has a mean salary of $75,000 a year and occupation B has the same
mean of $75,000 a year. Does this mean that the two groups are the same? Not
necessarily. Suppose that in group A, the salaries range from $65,000 to $85,000,
170 PART 3 Solving with Statistics
but in group B, they range from $35,000 to $115,000. This dierence— how much
the values dier from the mean— is called variance. Excel provides functions that
calculate and evaluate variance, and variance is an important part of many statis-
tical presentations.
Measuring variance
Variance is a measure of how spread out a set of data is in relation to the mean.
Variance is calculated by summing the squared deviations from the mean.
Mathematics that make you work
Specically, variance is calculated as follows:
1. Calculate the mean of the set of values.
2. Calculate the dierence from the mean for each value.
3. Square each dierence.
4. Sum up the squares.
5. Divide the sum of the squares by the number of items in the sample,
minus 1.
A sample is a selected set of values taken from the population. A sample is easier
to work with. For example, any statistical results found on 1,000 sales transac-
tions probably would return the same, or close to the same, results if run on the
entire population of 10,000 transactions.
Note that the last step diers depending on whether the VAR.S or VAR.P function
is used. VAR.S uses the number of items, minus 1, as the denominator. VAR.P uses
the number of items.
Figure 9-4 shows these steps in calculating a variance without using Excel’s
built-in function for the task. Column B has a handful of values. Column C shows
the deviation of each gure from the mean of the values. The mean, which equals
7.8, is never actually shown. Instead, the mean is calculated within the formula
that computes the dierence. For example, cell C8 has this formula:
=B8-AVERAGE($B$4:$B$8)
Column D squares the values in column C.This is an easy calculation. Here are the
contents of cell D8: =C8^2. Finally, the sum of the squared deviations is divided by
the number of items, less one item. The formula in cell D12 is =SUM(D4:D8)/
(COUNT(B4:B8)-1).
CHAPTER 9 Throwing Statistics aCurve 171
Functions that do the work: VAR.S and VAR.P
Now that you know how to create a variance the textbook way, you can forget it
all! Here, I show the mathematical steps so you can understand what happens, but
Excel provides the VAR.S and VAR.P functions to do all the grunt work for you.
In Figure 9-4, earlier in this chapter, cell D15 shows the variance calculated
directly with the VAR.S function: =VAR.S(B4:B8).
Try it yourself. Here’s how:
1. Type a list of numerical values.
Any mix of numbers will do.
2. Position the cursor in the cell where you want the variance to appear.
3. Type =VAR.S( to start the function.
4. Drag the pointer over the list or type the address of the range.
5. Type ) and press Enter.
Variance is calculated on a population of data or a sample of the population:
»
The VAR.S function calculates variance on a sample of a population’s data.
»
The VAR.P function calculates variance on the full population.
The calculation is slightly dierent in that the denominator for variance of a pop-
ulation is the number of items. The denominator for variance of a sample is the
number of items less one. Figure9-5 shows how VAR.S and VAR.P are used on a
sample and the full population. Cells A4:A43 contain the number of hours spent
watching TV daily by 40 individuals.
FIGURE9-4:
Calculating
variance from the
mean.
172 PART 3 Solving with Statistics
The VAR.S function calculates the variance of a sample of 20 values. The VAR.P
function calculates the variance of the full population of 40 values. VAR.P is typed
in the same fashion as VAR.S.Here’s how:
1. Type a list of numerical values.
Any mix of numbers will do.
2. Position the cursor in the cell where you want the variance to appear.
3. Type =VAR.P( to start the function.
4. Drag the pointer over the list or type the address of the range.
5. Type ) and press Enter.
Analyzing deviations
Often, nding the mean is an adequate measure of a sample of data. Sometimes,
the mean is not enough— you also want to know the average deviation from the
mean. That is, you want to nd the average of how far individual values dier
from the mean of the sample. For example, you may need to know the average
score on a test and how far the scores, on average, dier from the mean. Average
deviation is another way to specify variance.
Here’s an example:
Score Deviation from 84.83 Mean
78 6.83
92 7.17
FIGURE9-5:
Calculating
variance from the
mean.
CHAPTER 9 Throwing Statistics aCurve 173
Score Deviation from 84.83 Mean
97 12.17
80 4.83
72 12.83
90 5.17
The mean of this sample of values is 84.83. Use the AVERAGE function, if you want
to double-check. Each individual value deviates somewhat from the mean. For
example, 92 has a deviation value of 7.17 from the mean. A simple equation proves
this: 92– 84.83 = 7.17.
If you use the AVERAGE function to get the mean of the deviations, you have the
average deviation. It’s even easier than that, though. Excel provides the AVEDEV
function for this very purpose! AVEDEV calculates the mean and averages the
deviations all in one step.
Here’s how to use the AVEDEV function:
1. Type a list of numerical values.
2. Position the cursor in the cell where you want the average deviation to
appear.
3. Type =AVEDEV( to start the function.
4. Drag the pointer over the list or type the address of the range.
5. Type ) and press Enter.
The AVEDEV function averages the absolute deviations. In other words, negative
deviations (where the data point is less than the mean) are converted to positive
values for the calculation. For example, a value of 10 has a deviation of –40 from
a mean of 50: 10– 50 = –40. However, AVEDEV uses the absolute value of the
deviation, 40, instead of –40.
The variance, explained earlier in the chapter, serves as the basis for a common
statistical value called the standard deviation. Technically speaking, the standard
deviation is the square root of the variance. Variance is calculated by squaring
deviations from the mean.
The variance and the standard deviation are both valid measurements of
deviation. However, the variance can be a confusing number to work with. In
Figure9-4, earlier in this chapter, the variance is calculated to be 17.7 for a group
174 PART 3 Solving with Statistics
of values whose range is just 11 (14– 3). How can a range that is only a size of 11
show a variance of 17.7? Well, it does, as shown in Figure9-4.
This oddity is removed when you use the standard deviation. The reversing of the
squaring brings the result back to the range of the data. The standard deviation
value ts inside the range of the sample values. In addition, you’ll nd the stand-
ard deviation is more commonly used than the variance in statistical analyses.
Excel has a standard deviation formula: STDEV.P.This is how you use it:
1. Type a list of numerical values.
2. Position the cursor in the cell where you want the standard deviation to
appear.
3. Type =STDEV.P( to start the function.
4. Drag the pointer over the list or type the address of the range.
5. Type ) and press Enter.
Figure9-6 takes the data and variance shown in Figure9-4 and adds the standard
deviation to the picture. The standard deviation is 3.762977544. This number ts
inside the range of the sample data.
Looking for normal distribution
The standard deviation is one of the most widely used measures in statistical
work. It’s often used to analyze deviation in a normal distribution. A distribution
is the frequency of occurrences of values in a population or sample. A normal
FIGURE9-6:
Calculating the
standard
deviation.
CHAPTER 9 Throwing Statistics aCurve 175
distribution often occurs in large data sets that have a natural, or random, attrib-
ute. For example, taking a measurement of the height of 1,000 10-year-old chil-
dren will produce a normal distribution. Most of the measured heights center on
and deviate somewhat from the mean. A few measured heights will be extreme—
both considerably larger than the mean and considerably smaller than the mean.
Ringing the bell curve
A normal distribution is often visually represented as a graph in the shape of
a bell — hence, the popular term bell curve. Figure 9-7 shows a normal
distribution.
A normal distribution has some key characteristics:
»
The curve is symmetrical around the mean. Half the measurements are
greater than the mean, and half are less than the mean.
»
The mean, median, and mode are the same.
»
The highest point of the curve is the mean.
»
The width and height are determined by the standard deviation. The larger
the standard deviation, the wider and atter the curve. You can have two
normal distributions with the same mean and dierent standard deviations.
»
68.2 percent of the area under the curve is within one standard deviation of
the mean (both to the left and the right), 95.44 percent of the area under the
curve is within two standard deviations, and 99.72 percent of the area under
the curve is within three standard deviations.
»
The extreme left and right ends of the curve are called the tails. Extreme
values are found in the tails. For example, in a distribution of height, very
short heights are in the left tail, and very large heights are in the right tail.
FIGURE9-7:
Displaying a
normal
distribution in a
graph.
176 PART 3 Solving with Statistics
Dierent sets of data almost always produce dierent means and standard devia-
tions and, therefore, dierent-shaped bell curves. Figure9-8 shows two super-
imposed normal distributions. Each is a perfectly valid normal distribution;
however, each has its own mean and standard deviation, with the narrower curve
having a smaller standard deviation.
Analysis is often done with normal distributions to determine probabilities. For
example, what is the probability that a 10-year-old child’s height is 54 inches?
Somewhere along the curve is a discrete point that represents this height. Further
computation (outside the scope of this discussion) returns the probability. What
about nding the probability that a 10-year-old is 54 inches high or greater? Then
the area under the curve is considered. These are the type of questions and answers
determined with normal distributions.
A good amount of analysis of normal distributions involves the values in the tails:
the areas to the extreme left and right of the normal distribution curve.
All normal distributions have a mean and a standard deviation. However, the
stand ard normal distribution is characterized by having the mean equal 0 and the
standard deviation equal 1.
A table of values serves as a lookup in determining probabilities for areas under
the standard normal curve. This table is useful for working with data that has
been modied to t the standard normal distribution. This table is often found in
the appendix section of statistics books and on the Internet as well. A search on
the Internet for “areas under the normal standard curve” returns many useful
results.
Using STANDARDIZE
To use this table of standard normal curve probabilities, you must standardize the
data being analyzed. Excel provides the STANDARDIZE function for just this
FIGURE9-8:
Normal
distributions
come in dierent
heights and
widths.
CHAPTER 9 Throwing Statistics aCurve 177
purpose. STANDARDIZE takes three arguments: the data point, the mean, and the
standard deviation. The returned value is what the data point value is when the
mean is 0 and the standard deviation is 1.
An individual value from a nonstandard normal distribution is referred to as x. An
individual value from a standard normal distribution is referred to as z.
Figure9-9 shows how the STANDARDIZE function changes raw values to stand-
ard values. The standard deviation of the raw data is 7.438637452, but the stand-
ard deviation of the standardized values is 1. The mean of the standardized values
is 0.
Column B in Figure 9-9 has a long list of 1,200 random values. The mean is
17.23473829, as shown in cell C2. The standard deviation is 7.438637452, as shown
in cell C3. For each data point in column B, the standardized value is displayed
in column E. The list of values in column E are those returned with the
STANDARDIZEfunction.
The STANDARDIZE function takes three arguments:
»
Data point
»
Mean of the distribution
»
Standard deviation of the distribution
FIGURE9-9:
Standardizing a
distribution of
data.
178 PART 3 Solving with Statistics
For example, this is the formula in cell E7:
=STANDARDIZE(B7,C$2,C$3)
Note that a few key properties of the distribution have changed after the values are
standardized:
»
The standard deviation is 1.
»
The mean is 0.
»
The standardized values fall within the range –1.77 to 1.72.
This third point is determined by using the MIN and MAX functions, respectively,
in cells I7 and I8. Having values fall in the range –1.7 to 1.7 allows the values to be
analyzed with the Areas Under the Standard Normal Curve table mentioned ear-
lier. That is, it’s a property of standard normal curves to have all values t into
this range.
Here’s how to use the STANDARDIZE function:
1. Type a list of numerical values in a column.
It makes sense if this list is a set of random observable data, such as heights,
weights, or amounts of monthly rainfall.
2. Calculate the mean and standard deviation.
See “Getting Stuck in the Middle with AVERAGE, MEDIAN, and MODE” earlier in
this chapter for more about the mean.
The STANDARDIZE function references these values. The mean is calculated
with the AVERAGE function, and the standard deviation is calculated with the
STDEV.P function. STDEV.P is used instead of STDEV.S because the whole data
population is used.
3. Place the cursor in the cell adjacent to the rst data point typed in Step 1.
4. Type =STANDARDIZE( to start the function.
5. Click the cell that has the rst data point.
6. Type a comma (,).
7. Click the cell that has the mean.
8. Type a comma (,).
9. Click the cell that has the standard deviation.
10. Type ) to end the function.
CHAPTER 9 Throwing Statistics aCurve 179
The formula with the STANDARDIZE function is now complete. However, you
must edit it to x the references to the mean and standard deviation. The
references need to be made absolute so they won’t change when the formula
is dragged down to other cells.
11. Double-click the cell with the formula to enter the edit mode.
12. Precede the column and row parts of the reference to the cell that
contains the mean with a dollar sign ($).
13. Precede the column and row parts of the reference to the cell that
contains the standard deviation with a dollar sign ($).
14. Press Enter or press the Tab key to end the editing.
15. Use the ll handle to drag the formula down to the rest of the cells that
are adjacent to the source data points.
It’s important that the references to the mean and standard deviation are
treated as absolute references so they won’t change when the formula is dragged
to the other cells. Therefore, the formula should end up looking like this:
=STANDARDIZE(B7,$C$2,$C$3). Note the dollar signs.
Skewing from the norm
There is deviation in a distribution, but who says the deviation has to be uniform
with deviation the same on both sides of the mean? Not all distributions are normal.
Some are skewed, with more values clustered either below the mean or above it:
»
When more values fall below the mean, the distribution is positively skewed.
»
When more values fall above the mean, the distribution is negatively skewed.
The following table has a few examples.
Values Mean Comment
1, 2, 3, 4, 5 3There is no skew. An even number of values fall above
and below the mean.
1, 2, 3, 6, 8 4The distribution is positively skewed. More values fall
below the mean.
1, 2, 8, 9, 10 6The distribution is negatively skewed. More values fall
above the mean.
Figure9-10 shows a distribution plot, where 1,000 values are in the distribution,
ranging between 1 and 100. The values are summarized in a table of frequencies
(discussed later in this chapter). The table of frequencies is the source of the chart.
180 PART 3 Solving with Statistics
The mean of the distribution is 53.669, shown in cell D17. Cells D19 and D20 show
the number of values that fall above and below the mean. There are more values
above the mean than below. The distribution, therefore, is negatively skewed.
The actual skew factor is –0.27323459. The formula in cell D22 is =SKEW(A1:A1000).
The chart makes it easy to see the amount of skew. The plot is leaning to the right.
Finding out the amount of skew in a distribution can help identify bias in the data.
If, for example, the data is expected to fall into a normal (unskewed) distribution
(such as a random sampling of height for 10-year-old children) and the data is
skewed, you have to wonder whether some bias got into the data. Perhaps some
14-year-old children were measured by mistake and those heights were mixed in
with the data. Of course, being skewed is not itself an indication of bias. Some
distributions are skewed by their very nature.
SKEW
Here’s how to use the SKEW function to determine the skewness of a
distribution:
1. Type a list of numerical values.
2. Position the cursor in the cell where you want the amount of skew to
appear.
3. Type =SKEW( to start the function.
4. Drag the pointer over the list or type the address of the range.
5. Type ) and press Enter.
FIGURE9-10:
Working with
skewed data.
CHAPTER 9 Throwing Statistics aCurve 181
KURT
Another way that a distribution can dier from the normal distribution is kurtosis.
This is a measure of how peaked or at a distribution is compared with the normal
distribution. It is also a measure of the size of the curves’ tails. You determine
kurtosis with the KURT function, which returns a positive value if the distribution
is relatively peaked with small tails compared with the normal distribution. A
negative result means that the distribution is relatively at with large tails.
Figure9-11 shows the curves of two distributions. The one on the left has a nega-
tive kurtosis of –0.82096, indicating a somewhat at distribution. The distribu-
tion on the right is above 1, which means that the distribution has a pronounced
peak and relatively shorter tails.
This is how to use the KURT function:
1. Type a list of numerical values.
2. Position the cursor in the cell where you want result to appear.
3. Type =KURT( to start the function.
4. Drag the pointer over the list or type the address of the range.
5. Type ) and press Enter.
Comparing data sets
At times, you may need to compare two sets of data to see how they relate to each
other. For example, how does the amount of snowfall aect the number of
FIGURE9-11:
Measuring the
kurtosis of two
distributions.
182 PART 3 Solving with Statistics
customers entering a store? Does the money spent on advertising increase the
number of new customers? You answer these questions by determining whether
the two data sets are correlated.
Excel provides two functions for this task: COVARIANCE.S (or COVARIANCE.P) and
CORREL.These functions return the covariance and correlation coecient results
from comparing two sets of data.
COVARIANCE.S and COVARIANCE.P
Either COVARIANCE function takes two arrays as its arguments and returns a sin-
gle value. The value can be positive or negative. A positive value means that the
two arrays of data tend to move in the same direction: If data set A increases (or
decreases), data set B also increases (or decreases). A negative value means that
the two data sets tend to move in opposite directions: When A increases, B
decreases, and vice versa. The covariance’s absolute value reects the strength of
the relationship.
When COVARIANCE.S or COVARIANCE.P returns 0, there is no relationship between
the two sets of data.
Sales of bread will likely create sales of butter; they’re somewhat related. In other
words, the amount of butter a store sells is likely to follow the amount of bread it
sells: more bread, more butter.
Day Loaves of Bread Sold Tubs of Butter Sold
Monday 62 12
Tuesday 77 15
Wednesday 95 26
As bread sales increase, so do sales of butter. Therefore, sales of butter are expected
to have a positive relation to sales of bread. These items complement each other.
By contrast, bread and muns compete against each other. As bread is purchased,
the sales of muns likely suer because people will eat one or the other. Without
even using any function, you can conclude that bread sales and butter sales move
in the same direction and that bread sales and mun sales move in diering
directions. But by how much?
Figure9-12 shows an example that measures snowfall and the number of cus-
tomers coming into a store. Two covariance calculations are given: one for snow-
fall between 0 and 3 inches, and one for snowfall between 0 and 8 inches.
CHAPTER 9 Throwing Statistics aCurve 183
In Figure9-12, the rst COVARIANCE measures the similarity of the amount of
snowfall with the number of customers, but just for 0 to 3 inches of snow. The
formula in cell G7 is =COVARIANCE.P(B5:B8,D5:D8). The answer is –6.875. This
means that as snowfall increases, the number of customers decreases. The two
sets of data go in opposite directions. As one goes up, the other goes down. This is
conrmed by the result being negative.
The formula in cell G12 is =COVARIANCE.P(B5:B13,D5:D13). This examines all the
values of the data sets, inclusive of 0 to 8 inches of snow. The covariance is
–47.7778. This, too, conrms that as snowfall increases, the number of customers
decreases.
However, note that the covariance of the rst calculation, for 0 to 3 inches of
snow, is not as severe as the second calculation for 0 to 8 inches. When there are
just up to 3 inches of snow on the ground, some customers stay away— but not
that many. On the other hand, when there are 8 inches of snow, no customers
show up. The rst covariance is comparably less than the second: –6.875 versus
–48.2222. The former number is closer to 0 and tells you that a few inches of snow
don’t have much eect. The latter number is signicantly distanced from 0, and
sure enough, when up to 8 inches of snow is considered, customers stay home.
Note that the COVARIANCE.P function is used for the data in rows 5 through 8
because those data points are being considered as a population, not as a sample of
a population.
FIGURE9-12:
Using
COVARIANCE to
look for a
relationship
between two
data sets.
184 PART 3 Solving with Statistics
Here’s how to use the COVARIANCE.P function:
1. Type two lists of numbers.
The lists must be the same size.
2. Position the cursor in the cell where you want the result to appear.
3. Type =COVARIANCE.P( to start the function.
4. Drag the pointer over the rst list or type the address of the range.
5. Type a comma (,).
6. Drag the pointer over the second list or type the address of the range.
7. Type ) and press Enter.
CORREL
The CORREL function works in the same manner as COVARIANCE, but the result
is always between –1 and 1. The result is, in eect, set to a standard. Then the
results of correlations can be compared.
A negative result means that there is an inverse correlation. As one set of data goes
up, the other goes down. The actual negative value tells you to what degree the
inverse correlation is. A value of –1 means the two sets of data move perfectly in
opposite directions. A value of –0.5, for example, means that the two sets move in
somewhat opposite directions.
The CORREL function returns a value between –1 and 1. A positive value means
that the two data sets move in the same direction. A negative value means that the
two sets of data move in opposite directions. A value of 0 means that there is no
relation between the sets of data.
Figure9-13 shows three correlation results. The correlations display how custom-
ers reacted (as a percentage increase in sales) with regard to three types of adver-
tising. All three advertising campaigns show a positive correlation. As more money
is spent on advertising, customer responsiveness increases (or at least doesn’t
reverse its direction).
All three returned correlation values fall within the range of 0 to 1 and, therefore,
are easy to compare. The evidence is clear: Direct mail is not as ecient as maga-
zine or radio advertising. Both the magazine and radio advertising score high; the
returned values are close to 1. However, direct mail returns a correlation of 0.4472.
A positive correlation does exist — that is, direct-mail expenditures create an
increase in customer responsiveness. But the correlation is not as strong as maga-
zine or radio advertising. The money spent on direct mail would be better spent
elsewhere.
CHAPTER 9 Throwing Statistics aCurve 185
Here’s how to use the CORREL function:
1. Type two lists of numbers.
The lists must be the same size.
2. Position the cursor in the cell where you want the result to appear.
3. Type =CORREL( to start the function.
4. Drag the pointer over the rst list or type the address of the range.
5. Type a comma (,).
6. Drag the pointer over the second list or type the address of the range.
7. Type ) and press Enter.
Analyzing Data with Percentiles and Bins
No, not with trash bins (although you may want to throw your data out at times)!
The term bins refers to analyzing data by determining how many data points fall
into specied ranges, or bins. Percentiles is a technique for analyzing data by
determining where values relate, percentage-wise, to the entire data set.
Imagine this: A pharmaceutical company is testing a new drug to lower choles-
terol. The data is 500 cholesterol readings from the people in the sample. Of
FIGURE9-13:
Comparing the
results of
advertising
campaigns.
186 PART 3 Solving with Statistics
interest is how the data breaks up with regard to the 25 percent, the 50 percent,
and the 75 percent marks. That is, what cholesterol reading is greater than
25 percent of the data (and, therefore, smaller than 75 percent of the data)? What
value is at the 50 percent position? These measures are called quartiles because
they divide the sample into four quarters.
QUARTILE.INC and QUARTILE.EXC
The QUARTILE function is designed specically for this kind of analysis. The
function takes two arguments. One argument is the range of the sample data, and
the other indicates which quartile to return. The second argument can be 0, 1, 2,
3, or 4 when you’re using QUARTILE.INC; or 1, 2, or 3 when you’re using QUAR-
TILE.EXC.QUARTILE.EXC is used when the minimum and maximum values are to
be excluded. Therefore, that version of the function does not take 0 or 4 as the
second argument:
Formula Result
=QUARTILE.INC(A4:A503,0) Minimum value in the data
=QUARTILE.INC(A4:A503,1) Value at the 25th percentile
=QUARTILE.INC(A4:A503,2) Value at the 50th percentile
=QUARTILE.INC(A4:A503,3) Value at the 75th percentile
=QUARTILE.INC(A4:A503,4) Maximum value in the data
QUARTILE.INC (or QUARTILE.EXC) works on ordered data, but you don’t have to
do the sorting; the function takes care of that. In Figure9-14, the quartiles have
been calculated. The minimum and maximum values have been returned by using
0 and a 4, respectively, as the second argument.
Here’s how to use the QUARTILE function:
1. Type a list of numerical values.
2. Position the cursor in the cell where you want a particular quartile to
appear.
3. Type =QUARTILE.INC( to start the function.
4. Drag the pointer over the list or type the address of the range.
5. Type a comma (,).
6. Type a value between 0 and 4 for the second argument.
7. Type ) and press Enter.
CHAPTER 9 Throwing Statistics aCurve 187
PERCENTILE.INC and PERCENTILE.EXC
The PERCENTILE functions are similar to the QUARTILE functions except that you
can specify which percentile to use when returning a value. You aren’t locked into
xed percentiles such as 25, 50, or 75.
PERCENTILE.INC (or PERCENTILE.EXC) takes two arguments:
»
Range of the sample
»
Value between 0 and 1
The value tells the function which percentile to use. For example, 0.1 is the 10th
percentile, 0.2 is the 20th percentile, and so on.
Use the QUARTILE.INC function to analyze data at the xed 25th, 50th, and
75th percentiles. Use the PERCENTILE.INC function to analyze data at any desired
percentile. PERCENTILE.EXC is used when the second argument is exclusive of
0 and 1. In other words, the second argument can be any value between 0 and 1 but
not 0 or 1.
Figure 9-15 shows a sample of test scores. Who scored at or above the
90th percentile? The highest-scoring students deserve some recognition. Bear in
mind that scoring at the 90th percentile is not the same as getting a score of
90. Values at or above the 90th percentile are those that are in the top 10 percent
of whatever scores are in the sample.
FIGURE9-14:
Finding out
values at quarter
percentiles.
188 PART 3 Solving with Statistics
It so happens that the score that is positioned at the 90th percentile is 80. Cell F4
has the formula =PERCENTILE.INC(B3:B27,0.9), which uses 0.9 as the second
argument.
The cells in C3:C27 all have a formula that tests whether the cell to the left, in
column B, is at or greater than the 90th percentile. For example, cell C3 has this
formula: =IF(B3>=PERCENTILE.INC(B$3:B$27,0.9), "A Winner!", "").
If the value in cell B3 is equal to or greater than the value at the 90th percentile,
cell C3 displays the text A Winner!. The value in cell B3 is 59, which doesn’t make
for a winner. On the other hand, the value in cell B5 is greater than 80, so cell C5
displays the message.
Here’s how to use the PERCENTILE.INC function:
1. Type a list of numerical values.
2. Position the cursor in the cell where you want the result to appear.
3. Type =PERCENTILE.INC( to start the function.
4. Drag the pointer over the list or type the address of the range.
5. Type a comma (,).
FIGURE9-15:
Using
PERCENTILE to
nd high scorers.
CHAPTER 9 Throwing Statistics aCurve 189
6. Type an integer or decimal value between 0 and 1 for the second
argument.
This tells the function what percentile to seek.
7. Type ) and press Enter.
RANK
The RANK.EQ or RANK.AVG function tells you the rank of a particular number—
in other words, where the value is positioned— within a distribution. In a sample
of ten values, for example, a number could be the smallest (rank = 1), the largest
(rank = 10), or somewhere in between. The function takes three arguments:
»
The number being tested for rank: If this number isn’t found in the data, an
error is returned.
»
The range to look in: A reference to a range of cells goes here.
»
A 0 or a 1, telling the function how to sort the distribution: A 0 (or if the
argument is omitted) tells the function to sort the values in descending order.
A 1 tells the function to sort in ascending order. The order of the sort makes a
dierence in how the result is interpreted. Is the value in question being
compared to the top value of the data or the bottom value?
The dierence between RANK.EQ and RANK.AVG is that if more than one value is
at the same rank, RANK.EQ uses the larger value, whereas RANK.AVG uses the
average of the values.
Figure9-16 displays a list of employees and the bonuses they earned. Suppose
that you’re the employee who earned $4,800. You want to know where you rank
in the range of bonus payouts. Cell F4 contains a formula with the RANK.EQ func-
tion: =RANK.EQ(C9,C3:C20). The function returns an answer of 4. Note that the
function was entered without the third argument. Leaving the third argument out
tells the function to sort the distribution in descending order. This makes sense
for determining how close to the top of the range a value is.
Follow these steps to use the RANK function:
1. Type a list of numerical values.
2. Position the cursor in the cell where you want the result to appear.
3. Type =RANK.EQ( to start the function.
190 PART 3 Solving with Statistics
4. Click the cell that has the value you want to nd the rank for or type its
address.
You can also just type the actual value.
5. Type a comma (,).
6. Drag the pointer over the list of values or type the address of the range.
7. If you want to have the number evaluated against the list in ascending
order, type a comma (,) and then type 1.
Descending order is the default and doesn’t require an argument to be typed.
8. Type ) and press Enter.
PERCENTRANK
The PERCENTRANK.INC or PERCENTRANK.EXC formula also returns the rank of a
value but tells you where the value is as a percentage. In other words, the
PERCENTRANK function may tell you that a value is positioned 20 percent into the
ordered distribution. PERCENTRANK takes three arguments:
»
The range of the sample.
»
The number being evaluated against the sample.
»
An indicator of how many decimal places to use in the returned answer. (This
is an optional argument. If it’s left out, three decimal places are used.)
FIGURE9-16:
Determining the
rank of a value.
CHAPTER 9 Throwing Statistics aCurve 191
PERCENTRANK.EXC is used when a rank between 0 and 100 percent (between 0
and 1) is to be returned, but not 0 or 1. In Figure9-16, earlier in this chapter, the
percentage rank of the $4,800 value is calculated to be 82.3 percent (0.823).
Therefore, $4,800 ranks at the 82.3 percent position in the sample. The formula
in cell F8 is =PERCENTRANK.INC(C3:C20,C9).
In the RANK.EQ function, the value being evaluated is the rst argument, and the
range of the values is the second argument. In the PERCENTRANK.INC function,
the order of these arguments is reversed.
Follow these steps to use the PERCENTRANK.INC function:
1. Type a list of numerical values.
2. Position the cursor in the cell where you want the result to appear.
3. Type =PERCENTRANK.INC( to start the function.
4. Drag the pointer over the list of values or type the address of the range.
5. Type a comma (,).
6. Click the cell that has the value you want to nd the rank for or type its
address.
You can also just enter the actual value.
7. If you want to have more or fewer than three decimal places returned in
the result, type a comma (,) and then type the number of desired decimal
places.
8. Type ) to end the function.
FREQUENCY
The FREQUENCY function places the count of values in a sample in bins. A bin
represents a range of values, such as 0–1 or 20–29. Typically, the bins used in an
analysis are the same size and cover the entire range of values. For example, if the
data values range from 1–100, you might create ten bins each, ten units wide. The
rst bin would be for values of 1 to 10, the second bin would be for values of 11 to
20, and so on.
FREQUENCY is an array function and requires
192 PART 3 Solving with Statistics
Figure9-17 illustrates this. There are 300 values in the range B3:B302. The values
are random, between 1 and 100. Cells D3 through D12 have been set as bins that
each cover a range of ten values. Note that for each bin, its number is the top of
the range it’s used for. For example, the 30 bin is used for holding the count of
how many values fall between 21 and 30.
A bin holds the count of values within a numeric range— the number of values
that fall into the range. The bin’s number is the top of its range.
The FREQUENCY is an array function and requires specic steps to be used cor-
rectly. Here is how it’s done:
1. Type a list of values.
This can be a lengthy list and likely represents some observed data, such as the
age of people using the library or the number of miles driven on the job.
Obviously, you can use many types of observable data.
2. Determine the high and low values of the data.
You can use the MAX and MIN functions for this.
3. Determine what your bins should be.
This is subjective. For example, if the data has values from 1 to 100, you can
use 10 bins that each cover a range of 10 values. Or you can use 20 bins that
each cover a range of 5 values. Or you can use 5 bins that each cover a range
of 20 values.
FIGURE9-17:
Setting up bins to
use with the
FREQUENCY
function.
CHAPTER 9 Throwing Statistics aCurve 193
4. Create a list of the bins by typing the high number of each bin’s range, as
shown in cells D3:D12in Figure9-17.
5. Click the rst cell where you want the output of FREQUENCY to be
displayed.
6. Drag down to select the rest of the cells.
There should now be a range of selected cells. The size of this range should
match the number of bins. Figure9-18 shows what the worksheet should look
like at this step.
7. Type =FREQUENCY( to start the function.
8. Drag the cursor over the sample data or type the address of the range.
9. Type a comma (,).
10. Drag the cursor over the list of bins or type the address of that range.
Figure9-19 shows what the worksheet should look like at this point.
11. Type ).
Do not press Enter.
12. Press Ctrl+Shift+Enter to end the function entry.
Hurray, you did it! You have typed an array function. All the cells in the range
where FREQUENCY was typed have the same exact formula. The returned values
in these cells are the count of values from the raw data that falls within the bins.
This is called a frequency distribution.
FIGURE9-18:
Preparing to type
the FREQUENCY
function.
194 PART 3 Solving with Statistics
Next, take this distribution and plot a curve from it:
1. Select the Count of Values Per Bin range data.
That’s E3:E12in this example.
2. Click the Insert tab on the Ribbon.
3. In the Charts section, click the Column Chart item to display a selection
of column chart styles (see Figure9-20).
FIGURE9-19:
Completing the
entry of the
FREQUENCY
function.
FIGURE9-20:
Preparing to plot
the frequency
distribution.
CHAPTER 9 Throwing Statistics aCurve 195
4. Select the desired chart style to create the chart.
Figure9-21 shows the completed frequency distribution chart.
A frequency distribution is also known as a histogram.
MIN and MAX
Excel has two functions— MIN and MAX— that return the lowest and highest
values in a set of data. These functions are simple to use. The functions take up to
255 arguments, which can be cells, ranges, or values.
Figure9-22 shows a list of home sales. What are the highest and lowest values?
Cell F4 displays the lowest price in the list of sales with this formula:
=MIN(C4:C1000). Cell F6 displays the highest price with this formula:
=MAX(C4:C1000).
Here’s how to use the MIN or MAX function:
1. Type a list of numerical values.
2. Position the cursor in the cell where you want the result to appear.
3. Type either =MIN( or =MAX( to start the function.
4. Drag the pointer over the list or type the address of the range.
5. Type ) and press Enter.
FIGURE9-21:
Displaying a
frequency
distribution as a
column chart.
196 PART 3 Solving with Statistics
MIN and MAX return the upper and lower values of the data. What if you need to
know the value of the second-highest price? Or the third-highest price?
LARGE and SMALL
The LARGE and SMALL functions let you nd a value that is positioned at a certain
point in the data. LARGE is used to nd the value at a position that is oset from
the highest value. SMALL is used to nd the value at a position that is oset from
the lowest value.
Figure9-22, earlier in this chapter, displays the top ve home sales, as well as the
bottom ve. Both the LARGE and SMALL functions take two arguments: the range
of the data in which to nd the value, and the position relative to the top or bottom.
The top ve home sales are found with LARGE.The highest sale, in cell F10, is
returned with this formula: =LARGE(C$4:C$1000,1). Because the function used
here is LARGE, and the second argument is 1, the function returns the value at the
rst position. By no coincidence, this value is also returned by the MAX function.
To nd the second-highest home sales, the second argument to LARGE is 2.
Cell F11 has this formula: =LARGE(C$4:C$1000,2). The third-, fourth-, and fth-
largest home sales are returned in the same fashion when 3, 4, and 5, respectively,
are used as the second argument.
FIGURE9-22:
Finding high and
low values.
CHAPTER 9 Throwing Statistics aCurve 197
The bottom ve sales are returned in the same fashion by the SMALL function. For
example, cell F22 has this formula: =SMALL(C$4:C$1000,1). The returned value,
$143,339, matches the value returned by the MIN function. The cell just above it,
F21, has this formula: =SMALL(C$4:C$1000,2).
Hey, wait! You may have noticed that the functions are looking down to row 1000
for values, but the bottom listing is numbered as 60. An interesting thing to note
in this example is that all the functions use row 1000 as the bottom row to look in,
but this doesn’t mean there are that many listings. This is intentional. There are
only 60 listings for now. What happens when new sales are added to the bottom
of the list? By giving the functions a considerably larger range than needed, you’ve
built in the ability to handle a growing list.
The labels in cells E10:E14 (#1, #2, and so on) are typed as is. Clearly, any ranking
that starts from the top would begin with # 1, proceed to # 2, and so on.
However, the labels in cells E18:E22 (#56, #57, and so on) were created with for-
mulas. The COUNTA function is used to count the total number of listings. Even
though the function looks down to row 1000, it nds only 60 listings, so that is the
returned count. The #60 label is based on this count. The other labels (#59, #58,
#57, and #56) are created by reducing the count by 1, 2, 3, and 4, respectively:
»
The formula in cell E22 is ="# " & COUNTA(B$4:B$1000).
»
The formula in cell E21 is ="# " & COUNTA(B$4:B$1000)-1.
»
The formula in cell E20 is ="# " & COUNTA(B$4:B$1000)-2.
»
The formula in cell E19 is ="# " & COUNTA(B$4:B$1000)-3.
»
The formula in cell E18 is ="# " & COUNTA(B$4:B$1000)-4.
Here’s how to use the LARGE and SMALL functions:
1. Type a list of numerical values.
2. Position the cursor in the cell where you want the result to appear.
3. Type =LARGE( or =SMALL( to start the function.
4. Drag the pointer over the list or type the address of the range.
5. Type a comma (,).
6. Type a number indicating the position to return.
7. Type ) and press Enter.
198 PART 3 Solving with Statistics
Use LARGE to nd a value’s position relative to the highest value. Use SMALL to
nd a value’s position relative to the smallest value.
Going for the Count
The COUNT, COUNTA, and COUNTIF functions return, well, a count. What else
could it be with names like that?
COUNT and COUNTA
COUNT is straightforward. It counts how many items are in a range of values.
There is a catch, though: Only numeric values and dates are counted. Text values
are not counted; neither are blank cells.
COUNTA works the same way as COUNT, but it counts all cells that are not empty,
including text cells.
To use the COUNT function, follow these steps:
1. Type a list of numerical values.
2. Position the cursor in the cell where you want the result to appear.
3. Type =COUNT( to start the function.
4. Drag the pointer over the list or type the address of the range.
5. Type ) and press Enter.
Figure9-23 shows a list of popular movies along with the sales gure and the year
for each movie. Cell F5 displays the count of movies, returned with the COUNT
function. The formula in cell F5 is =COUNT(C5:C329).
Note that the range typed in the function looks at the sales gures for the movies.
This is intentional. Sales gures are numeric. If COUNT used the range of movie
titles, in column B, the count would be 0 because this column contains text data.
COUNTIF
The COUNTIF function is handy when you need to count how many items are
inalist that meet a certain condition. In Figure9-23, earlier in this chapter,
cell F7 shows the count of movies made in 2002. The formula in cell F7 is
=COUNTIF(D5:D329,2002).
CHAPTER 9 Throwing Statistics aCurve 199
The COUNTIF function takes two arguments:
»
The range address of the list to be counted
»
The criterion
Table9-1 presents some examples of criteria for the COUNTIF function.
The criteria can also be based on text. For example, COUNTIF can count all occur-
rences of Detroit in a list of business trips. You can use wildcards with COUNTIF.
The asterisk (*) is used to represent any number of characters, and the question
mark (?) is used to represent a single character.
FIGURE9-23:
Counting with
and without
criteria.
TABLE9-1 Using Criteria with the COUNTIF Function
Example Comment
=COUNTIF(D5:D329, "=2002") Returns the count of movies made in 2002.
=COUNTIF(D5:D329,2002) Returns the count of movies made in 2002. Note that this is
unique in that the criteria do not need to be in double quotes
because the criterion is a simple equality.
=COUNTIF(D5:D329, "<2002") Returns the count of movies made before 2002.
=COUNTIF(D5:D329, ">=2002") Returns the count of movies made in or after 2002.
=COUNTIF(D5:D329, "<>2002") Returns the count of movies not made in 2002.
200 PART 3 Solving with Statistics
As an example, using an asterisk after Batman returns the number of Batman
movies listed in column B in Figure9-23 (earlier in this chapter). The formula
that does this looks like this: =COUNTIF(B5:B329, "Batman*"). Notice the asterisk
after Batman. This lets the function count Batman and Robin, Batman Returns, and
Batman Forever along with just Batman.
Your criterion can be typed in a cell rather than directly in the COUNTIF function.
Then just use the cell address in the function. For example, if you type “Batman*”
in cell C1, =COUNTIF(B5:B329,C1) it would show the same result as the previous
example. Cell F11 in Figure9-23 returns the count of movies that have earned
more than $200,000,000. The formula is =COUNTIF(C5:C329, ">200000000").
What if you need to determine the count of data items that match two conditions?
Can do! The formula in cell F15 returns the count of movies that were made in
2004 and earned more than $200,000,000. However, COUNTIF is not useful for
this type of multiple condition count. Instead, the SUMPRODUCT function is used.
The formula in cell F15 follows:
=SUMPRODUCT((C5:C329>200000000)*(D5:D329=2004))
Believe it or not, this works. Although this formula looks like it’s multiplying the
number of movies that earned at least $200,000,000 by the number of movies
made in 2004, it’s really returning the count of movies that meet the two condi-
tions. (Quick trivia: Which two 1998 movies earned at least $200,000,000? The
answer [drum roll, please]: Armageddon and Saving Private Ryan.)
To use the COUNTIF function, follow along:
1. Type a list of numerical values.
2. Position the cursor in the cell where you want the result to appear.
3. Type =COUNTIF( to start the function.
4. Drag the pointer over the list or type the address of the range.
5. Type a comma (,).
6. Type a condition and enclose the condition in double quotes.
Use the following as needed:
•
= (equal to)
•
> (greater than)
•
< (less than)
•
* (wildcard)
CHAPTER 9 Throwing Statistics aCurve 201
•
? (wildcard)
•
<> (not equal to)
7. Type ) and press Enter.
The result is a count of cells that match the condition.
There is also a COUNTIFS function. This function allows using multiple ranges
and criteria to return a count. COUNTIFS is quite similar to SUMIFS, discussed in
Chapter8.
CHAPTER 10 Using Signicance Tests 203
Chapter10
Using Signicance Tests
When you have data from a population, you can draw a sample and run
your statistical analysis on the sample. You can also run the analysis on
the population itself. Is the mean of the sample data the same as the
mean of the whole population? You can calculate the mean of both the sample and
the population and then know precisely how well the sample represents the popu-
lation. Are the two means exact? O a little bit? How much dierent?
The problem with this, though, is that getting the data of the entire population in
the rst place isn’t always feasible. On average, how many miles per gallon does
a Toyota Camry get after 5 years on the road? You cannot answer this question to
an exact degree because it’s impossible to test every Camry out there.
Instead, you infer the answer. Testing a handful, or sample, of Camrys is certainly
possible. Then the mean gas mileage of the sample is used to represent the mean
gas mileage of all 5-year-old Camrys. The mean of the sample group will not nec-
essarily match the mean of the population, but it is the best value that can be
attained.
This type of statistical work is known as estimation, or inferential statistics. In this
chapter, I show you the functions that work with the Student’s t-test, useful for
gaining insight into the unknown population properties. This is the method of
choice when you’re using a small sample— say, 30 data points or less.
IN THIS CHAPTER
»
Understanding estimation statistics
»
Using the Student’s t-distribution test
functions
»
Analyzing probabilities and results
with the chi square functions
204 PART 3 Solving with Statistics
The tests presented in this chapter deal with probabilities. If the result of a test—
a t-test, for example— falls within a certain probability range, the result is said
to be signicant. Outside that range, the result is considered to be nonsignicant.
A common rule of thumb is to consider probabilities less than 5 percent, or 0.05,
to be signicant, but exceptions to this rule exist.
The Student’s t-test has nothing to do with students. The originator of the method
was not allowed to use his real name due to his employer’s rules. Instead, he used
the name Student.
Testing to the T
The TTEST function returns the probability that two samples come from popula-
tions that have the same mean. For example, a comparison of the salaries of
accountants and professors in NewYork City is under way. Are the salaries, overall
(on average), the same for these two groups? Each group is a separate population,
but if the means are the same, the average salaries are the same.
Polling all the accountants and professors isn’t possible, so a sample of each is
taken. Twenty-ve random members of each group divulge their salaries in the
interest of the comparison. Figure10-1 shows the salaries of the two groups, as
well as the results of the TTEST function.
FIGURE10-1:
Comparing
salaries.
CHAPTER 10 Using Signicance Tests 205
The TTEST function returns 10.6 percent (0.106437) based on how the arguments
of the function were typed. This percentage says there is a 10.6 percent probability
that the mean of the underlying populations is the same. Said another way, this is
the likelihood that the mean of all accountant salaries in NewYork City matches
the mean of all professor salaries in New York City. The formula in cell E8 is
=TTEST(A2:A26,B2:B26,2,2).
The arguments of the TTEST function are listed in Table10-1.
The third argument of TTEST tells whether to conduct a one-tailed or two-tailed
test. A one-tailed test is used when there is a question of whether one set of data
is specically larger or smaller than the other. A two-tailed test is used to tell
whether the two sets are just dierent without specifying larger or smaller.
The rst two arguments to TTEST are the ranges of the two sets of values. A per-
tinent consideration here is how the two sets of data are related. The sets could be
comprised of elements that have a corresponding member in each set. For exam-
ple, there could be a set of “before” data and a set of “after” data (see Table10-2).
TABLE10-1 Arguments of the TTEST Function
Argument Comment
Array 1 The reference to the range of the rst array of data.
Array 2 The reference to the range of the second array of data.
Tails Either 1 or 2. For a one-tailed test, type 1. For a two-tailed test, type 2.
Type Type of t-test to perform. The choice is 1, 2, or 3. A number 1 indicates a
paired test. A number 2 indicates a two-sample test with equal variance.
A number 3 indicates a two-sample test with unequal variance.
TABLE10-2 Working with Paired Data
Seedling Height at Week 1 Height at Week 2
#1 4 inches 5 inches
#2 3¾ inches 5 inches
#3 4½ inches 5½ inches
#4 5 inches 5 inches
206 PART 3 Solving with Statistics
This type of data is typed in the function as paired. In other words, each data value
in the rst sample is linked to a data value in the second sample. In this case, the
link is due to the fact that the data values are “before” and “after” measurements
from the same seedlings. Data can be paired in other ways. In the salary survey,
for example, each accountant may be paired with a professor of the same age to
ensure that length of time on the job does not aect the results. In this case, you
would also use a paired t-test.
When you’re using TTEST for paired samples, the two ranges typed for the rst
and second arguments must be the same size. When you’re comparing two inde-
pendent (unpaired) samples, the two samples don’t have to be the same size.
Use TTEST to determine the probability that two samples come from the same
population.
Here’s how to use the TTEST function:
1. Type two sets of data.
2. Position the cursor in the cell where you want the result to appear.
3. Type =TTEST( to start the function.
4. Drag the pointer over the rst list or type the address of its range.
5. Type a comma (,).
6. Drag the pointer over the second list or type the address of its range.
7. Type a comma (,).
8. Type 1 for a one-tailed test, or type 2 for a two-tailed test.
9. Type a comma (,).
10. Type one of the following:
•
1 for a paired test
•
2 for a test of two samples with equal variance
•
3 for a test of two samples with unequal variance
11. Type ).
If you’ve ever taken a statistics course, you may recall that a t-test returns a
t-value, which you then had to look up in a table to determine the associated prob-
ability. Excel’s TTEST function combines these two steps. It calculates the t-value
internally and determines the probability. You never see the actual t-value, just
the probability— which is what you’re interested in anyway!
CHAPTER 10 Using Signicance Tests 207
The TDIST function returns the probability for a given t-value and degrees of
freedom. You would use this function if you had a calculated t-value and
wanted to determine the associated probability. Note that the TTEST function
doesn’t return a t-value but a probability, so you wouldn’t use TDIST with the
result that is returned by TTEST.Instead, you would use TDIST if you had one or
more t-values calculated elsewhere and needed to determine the associated
probabilities.
TDIST takes three arguments:
»
The t-value
»
The degrees of freedom
»
The number of tails (one or two)
A t-distribution is similar to a normal distribution. The plotted shape is a bell
curve. However, a t-distribution diers, particularly in the thickness of the tails.
How much so is dependent on the degrees of freedom. The degrees of freedom
roughly relate to the number of elements in the sample, less one. All t- distributions
are symmetrical around 0, as is the normal distribution. In practice, however, you
always work with the right half of the curve— positive t-values.
To use the TDIST function, follow these steps:
1. Position the cursor in the cell where you want the result to appear.
2. Type =TDIST( to start the function.
3. Type a value for t or click a cell that has the value.
4. Type a comma (,).
5. Type the degrees of freedom.
6. Type a comma (,).
7. Type one of the following:
•
1 for a one-tailed test
•
2 for a two-tailed test
8. Type ).
If the t-value is based on a paired test, the degrees of freedom is equal to 1 less
than the count of items in either sample. (Remember, the samples are the same
size.) When the t-value is based on two independent samples, the degrees of
freedom = (count of sample-1 items– 1) + (count of sample-2 items– 1).
208 PART 3 Solving with Statistics
The TINV function produces the inverse of TDIST. That is, TINV takes two
arguments— the probability and the degrees of freedom— and returns the value
of t. To use TINV, follow these steps:
1. Position the cursor in the cell where you want the result to appear.
2. Type =TINV( to start the function.
3. Type the probability value (or click a cell that has the value).
4. Type a comma (,).
5. Type the degrees of freedom.
6. Type ).
Comparing Results with an Estimate
The chi square test is a statistical method for determining whether observed
results are within an acceptable range compared with what the results were
expected to be. In other words, the chi square is a test of how well a before set of
results and an after set of results compare. Did the observed results come close
enough to the expected results that you can safely assume that there is no real
dierence? Or were the observed and expected results far enough apart that you
must conclude that there is a real dierence?
A good example is ipping a coin 100 times. The expected outcome is 50 times
heads, 50 times tails. Figure10-2 shows how a chi square test statistic is calcu-
lated in a worksheet without any functions.
FIGURE10-2:
Calculating a chi
square.
CHAPTER 10 Using Signicance Tests 209
Cells B5:B6 show the expected results— that heads and tails each show up 50
times. Cells C5:C6 show the observed results. Heads appeared 44 times, and tails
appeared 56 times. With this information, here is how the chi square test statistic
is calculated:
1. For each expected and observed pair, calculate the dierence as
(Expected– Observed).
2. Calculate the square of each dierence as (Expected– Observed)2.
3. Divide the squares from Step 2 by their respective expected values.
4. Sum the results of Step 3.
Of course, a comprehensive equation can be used for the rst three steps, such as
=(expected-observed)^2/expected.
The result in this example is 1.44. This number— the chi square value— is looked
up in a table of chi square distribution values. This table is a matrix of degrees of
freedom and condence levels. Seeing where the calculated value is positioned in
the table for the appropriate degrees of freedom (one less than the number of data
points) shows you the probability that the dierence between the expected and
observed values is signicant. That is, is the dierence within a reasonable error
of estimation, or is it real (for example, caused by an unbalanced coin)?
You can nd the table of degrees of freedom and condence levels in the appendix
of a statistics book or on the Internet.
The CHISQ.TEST function returns the probability value (p) derived from the
expected and observed ranges. The function has two arguments: the range of
observed (or actual) values and the range of expected values. These ranges must,
of course, contain the same number of values, and they must be matched (rst
item in the expected list is associated with the rst item in the observed list, and so
on). Internally, the function takes the degrees of freedom into account, calculates
the chi square statistic value, and computes the probability.
Use the CHISQ.TEST function this way:
1. Type two ranges of values as expected and observed results.
2. Position the cursor in the cell where you want the result to appear.
3. Type =CHISQ.TEST( to start the function.
4. Drag the cursor over the range of observed (actual) values or type the
address of the range.
5. Type a comma (,).
210 PART 3 Solving with Statistics
6. Drag the cursor over the range of expected values, or type the address of
the range.
7. Type ).
Figure10-3 shows a data set of expected and actual values. The chi square test
statistic is calculated as before, delivering a value of 1.594017, as shown in cell F12.
The CHISQ.TEST function, in cell D14, returns a value of 0.953006566 — the
associated probability. CHISQ.TEST doesn’t return the chi square statistic but the
associated probability.
Now tie in a relationship between the manually calculated chi square and the value
returned with CHISQ.TEST.If you looked up your manually calculated chi square
value (1.59) in a chi square table for degrees of freedom of 6 (one less than the
number of observations), you would nd it associated with a probability value of
0.95. Of course, the CHISQ.TEST function does this for you, returning the proba-
bility value, which is what you’re after. But suppose that you’ve manually calcu-
lated chi square values and want to know the associated probabilities. Do you have
to use a table? Nope— the CHISQ.DIST.RT function comes to the rescue. Further-
more, if you have a probability and want to know the associated chi square value,
you can use the CHISQ.INV.RT function.
The RT in the CHISQ.DIST.RT and CHISQ.INV.RT functions is the abbreviation for
Right Tail. The functions in the conguration work with the right tail of the
distribution.
FIGURE10-3:
Determining
probability.
CHAPTER 10 Using Signicance Tests 211
Figure 10-3, earlier in this chapter, demonstrates the CHISQ.DIST.RT and CHI.
SQ.INV.RT functions as well. CHISQ.DIST.RT takes two arguments: a value to be
evaluated for a distribution (the chi square value, 1.59in the example) and the
degrees of freedom (6in the example). Cell D16 displays 0.953006566, which is
the same probability value returned by the CHISQ.TEST function — just as it
should be! The formula in cell D16 is =CHISQ.DIST.RT(F12,6).
CHISQ.TEST and CHISQ.DIST.RT both return the same probability value but calcu-
late the result with dierent arguments. CHISQ.TEST uses the actual expected and
observed values and internally calculates the test statistic to return the probabil-
ity. This happens behind the scenes; just the probability is returned. CHISQ.DIST.
RT needs the test statistic fed in as an argument.
To use the CHISQ.DIST.RT function, follow these steps:
1. Position the cursor in the cell where you want the result to appear.
2. Type =CHISQ.DIST.RT( to start the function.
3. Click the cell that has the chi square test statistic.
4. Type a comma (,).
5. Type the degrees of freedom.
6. Type ).
The CHISQ.INV.RT function rounds out the list of chi square functions in Excel.
CHISQ.INV.RT is the inverse of CHISQ.DIST.RT.That is, with a given probability
and degrees of freedom number, CHISQ.INV.RT returns the chi square test
statistic.
Cell D18 in Figure 10-3, earlier in this chapter, has the formula =CHISQ.INV.
RT(D14,6). This returns the value of the chi square: 1.594017094. CHISQ.INV.RT is
useful when you know the probability and degrees of freedom and need to deter-
mine the chi square test statistic value.
To use the CHISQ.INV.RT function, follow these steps:
1. Position the cursor in the cell where you want the result to appear.
2. Type =CHISQ.INV.RT( to start the function.
3. Click the cell that has the probability.
212 PART 3 Solving with Statistics
4. Type a comma (,).
5. Type the degrees of freedom.
6. Type ).
Working with inferential statistics is dicult! I suggest further reading to help
with the functions and statistical examples discussed in this chapter. A great book
is Statistics For Dummies, 2nd Edition, by Deborah J.Rumsey, PhD (Wiley).
CHAPTER 11 Rolling the Dice onPredictions andProbability 213
Chapter11
Rolling the Dice
onPredictions
andProbability
When you’re analyzing data, one of the most important steps is usually to
determine what model ts the data. No, I’m not talking about a model
car or model plane! This is a mathematical model or, put another way, a
formula that describes the data. The question of a model is applicable to all data
that comes in x-y pairs, such as the following:
»
Comparisons of weight and height measurements
»
Data on salary versus educational level
»
Number of sh feeding in a river by time of day
»
Number of employees calling in sick as related to day of the week
IN THIS CHAPTER
»
Understanding linear and
exponential models
»
Using SLOPE and INTERCEPT to
describe linear data
»
Predicting future data from
existing data
»
Working with normal and Poisson
distributions
214 PART 3 Solving with Statistics
Modeling
Suppose now that you plot all the data points on a chart— a scatter chart, in Excel
terminology. What does the pattern look like? If the data is linear, the data points
fall more or less along a straight line. If they fall along a curve rather than a
straight line, they aren’t linear and are likely to be exponential. These two
models— linear and exponential— are the two most commonly used models, and
Excel provides functions for working with them.
Linear model
In a linear model, the mathematical formula that models the data is as follows:
y = mx + b
This formula tells you that for any x value, you calculate the y value by multiplying
x by a constant m and then adding another constant b. The value m is called the
line’s slope, and b is the y-intercept (the value of y when x = 0). This formula gives
a perfectly straight line, and real-world data doesn’t fall exactly on such a line.
The point is that the line, called the linear regression line, is the best t for the data.
The constants m and b are dierent for each data set.
Exponential model
In an exponential model, the following formula models the data:
y = bmx
The values b and m are, again, constants. Many natural processes, including
bacterial growth and temperature change, are modeled by exponential curves.
Figure11-1 shows an example of an exponential curve. This curve is the result of
the preceding formula when b = 2 and m = 1.03.
Again, b and m are constants that are dierent for each data set.
CHAPTER 11 Rolling the Dice onPredictions andProbability 215
Getting It Straight: Using SLOPE and
INTERCEPT to Describe Linear Data
As I discuss earlier in this chapter, many data sets can be modeled by a straight
line. In other words, the data is linear. The line that models the data, known as the
linear regression line, is characterized by its slope and its y-intercept. Excel pro-
vides the SLOPE and INTERCEPT functions to calculate the slope and y-intercept
of the linear regression line for a set of data pairs.
The SLOPE and INTERCEPT functions take the same two arguments:
»
The rst argument is a range or array containing the y values of the data set.
»
The second argument is a range or array containing the x values of the
data set.
FIGURE11-1:
An exponential
curve.
216 PART 3 Solving with Statistics
The two ranges must contain the same number of values; otherwise, an error
occurs. Follow these steps to use either of these functions:
1. In a blank worksheet cell, type =SLOPE( or =INTERCEPT( to start the
function entry.
2. Drag the mouse over the range containing the y data values or type the
range address.
3. Type a comma (,).
4. Drag the mouse over the range containing the x data values or type the
range address.
5. Type ) and press Enter.
When you know the slope and y-intercept of a linear regression line, you can cal-
culate predicted values of y for any x by using the formula y = mx + b where m is
the slope and b is the y-intercept. But Excel’s FORECAST and TREND functions
can do this for you.
Knowing the slope and intercept of a linear regression line is one thing, but what
can you do with this information? One very useful thing is to actually draw the
linear regression line along with the data points. This method of graphical presen-
tation is commonly used; it lets the viewer see how well the data ts the model.
To see how this is done, look at the worksheet in Figure11-2. Columns A and B
contain the x and y data, and the chart shows a scatter plot of this data. It seems
clear that the data is linear and that you can validly use SLOPE and INTERCEPT
with them.
The rst step is to put these functions in the worksheet, as follows. (You can use
any worksheet that has linear x and y data in it.)
FIGURE11-2:
The scatter plot
indicates that the
x and y data in
this worksheet
are linear.
CHAPTER 11 Rolling the Dice onPredictions andProbability 217
1. Type the label Slope in an empty cell.
2. In the cell to the right, type =SLOPE( to start the function entry.
3. Drag the mouse over the range containing the y data values or type the
range address.
4. Type a comma (,).
5. Drag the mouse over the range containing the x data values or type the
range address.
6. Type ).
7. Press Enter to complete the formula.
8. In the cell below the slope label, type the label Intercept.
9. In the cell to the right, type =Intercept(.
10. Drag the mouse over the range containing the y data values or type the
range address.
11. Type a comma (,).
12. Drag the mouse over the range containing the x data values or type the
range address.
13. Type ) and press Enter to complete the formula.
At this point, the worksheet displays the slope and intercept of the linear regres-
sion line for your data. The next task is to display this line on the chart, as follows:
1. If necessary, add a new empty column to the worksheet to the right of
the y value column.
To do this, click any cell in the column immediately to the right of the y value
column, and then, on the Home tab on the Ribbon, click the Insert button and
select Insert Sheet Columns.
2. Place the cursor in this column in the same row as the rst x value.
3. Type an equal sign (=) to start a formula.
4. Click the cell where the SLOPE function is located to type its address in
the formula.
5. Press F4 to convert the address to an absolute reference.
It displays with dollar signs.
6. Type the multiplication symbol (*).
7. Click the cell containing the x value for that row.
218 PART 3 Solving with Statistics
8. Type a plus sign (+).
9. Click the cell containing the INTERCEPT function to type its address in the
formula.
10. Press F4 to convert the address to an absolute reference.
It displays with dollar signs.
11. Press Enter to complete the formula.
12. Make sure the cursor is in the cell where you just typed the formula.
13. Press Ctrl+C to copy the formula to the Clipboard.
14. Hold down the Shift key and press the ↓ key until the entire column is
highlighted down to the row containing the last x value.
15. Press Enter to paste the copied formula to all selected cells.
At this point, the column of data you just created contains the y values for the
linear regression line. The nal step is to create a chart that displays both the
actual data and the computed regression line. Follow these steps:
1. Highlight all three columns of data: the x values, the actual y values, and
the computed y values.
2. Select the Insert tab on the Ribbon (as shown in Figure11-3).
3. Click the Scatter Chart button.
4. Select the basic Scatter Chart type.
5. Click the Finish button.
FIGURE11-3:
Creating a scatter
chart.
CHAPTER 11 Rolling the Dice onPredictions andProbability 219
The chart displays, as shown in Figure11-4. You can see two sets of points. The
scattered points are the actual data, and the straight line is the linear regres-
sion line.
What’s Ahead: Using FORECAST, TREND,
and GROWTH to Make Predictions
The FORECAST function does just what its name suggests: forecasts an unknown
data value based on existing, known data values. The function is based on a single
important assumption: that the data is linear. Exactly what does this mean?
FORECAST
The data that FORECAST works with is in pairs; there’s an x value and a corre-
sponding y value in each pair. Perhaps you’re investigating the relationship
between people’s heights and their weight. Each data pair would be one person’s
height— the x value— and that person’s weight— the y value. Many kinds of
data are in this form— sales by month, for example, or income as a function of
educational level.
You can use the CORREL function to determine the degree of linear relationship
between two sets of data. (See Chapter9 to nd out about the CORREL function.)
FIGURE11-4:
A data set
displayed with its
linear regression
line.
220 PART 3 Solving with Statistics
To use the FORECAST function, you must have a set of x and y data pairs. Then you
provide a new x value, and the function returns the y value that would be associ-
ated with that x value based on the known data. The function takes three
arguments:
»
The rst argument is the x value for which you want a forecast.
»
The second argument is a range containing the known y values.
»
The third argument is a range containing the known x values.
Note that the x and y ranges must have the same number of values; otherwise, the
function returns an error. The x and y values in these ranges are assumed to be
paired in order.
Don’t use FORECAST with data that isn’t linear. Doing so produces inaccurate
results.
Now you can work through an example of using FORECAST to make a prediction.
Imagine that you’re the sales manager at a large corporation. You’ve noticed that
the yearly sales results for each of your salespeople is related to the number of
years of experience each has. You’ve hired a new salesperson with 16 years of
experience. How much in sales can you expect this person to make?
Figure11-5 shows the existing data for salespeople— their years of experience
and annual sales last year. This worksheet also contains a scatter chart of the data
to show that it’s linear. It’s clear that the data points fall fairly well along a
straight line. Follow these steps to create the prediction:
1. In a blank cell, type =FORECAST( to start the function entry.
The blank cell is C24in Figure11-5.
2. Type 16, the x value for which you want a prediction.
3. Type a comma (,).
4. Drag the mouse over the y range or type the cell range.
C3:C17 is the cell range in the example.
5. Type a comma (,).
6. Drag the mouse over the x range or type the cell range.
B3:B17 is the cell range in the example.
7. Type ) and press Enter to complete the formula.
CHAPTER 11 Rolling the Dice onPredictions andProbability 221
After you format the cell as Currency, the result, shown in Figure11-5, displays
the prediction that your new salesperson will make $27,093in sales their rst
year. But remember: This is just a prediction, not a guarantee!
TREND
The preceding section shows how the FORECAST function can predict a y value for
a known x based on an existing set of linear x and y data. What if you have more
than one x value to predict? Have no fear; TREND is here! What FORECAST does for
a single x value, TREND does for a whole array of x values.
Like FORECAST, the TREND function is intended for working with linear data. If
you try to use it with nonlinear data, the results will be incorrect.
The TREND function takes up to four arguments:
»
The rst argument is a range containing the known y values.
»
The second argument is a range containing the known x values.
»
The third argument is a range containing the x values for which you want
predictions.
»
The fourth argument is a logical value. It tells the function whether to force
the constant b (the y-intercept) to 0. If the fourth argument is TRUE or omitted,
the linear regression line (used to predict y values) is calculated normally.
If this argument is FALSE, the linear regression line is calculated to go through
the origin (where both x and y are 0).
FIGURE11-5:
Forecasting sales.
222 PART 3 Solving with Statistics
Note that the ranges of known x and y values must be the same size (contain the
same number of values).
TREND returns an array of values, one predicted y for each x value. In other words,
it’s an array function and must be treated as such. (See Chapter3 for help with
array functions.) Specically, this means selecting the range where you want the
array formula results, typing the formula, and pressing Ctrl+Shift+Enter rather
than pressing Enter alone to complete the formula.
When would you use the TREND function? Here’s an example: You’ve started a
part-time business, and your income has grown steadily over the past 12 months.
The growth seems to be linear, and you want to predict how much you will earn in
the coming 6 months. The TREND function is ideal for this situation. Here’s how
to do it:
1. In a new worksheet, type the numbers 1 through 12, representing the
past 12 months, in a column.
2. In the adjacent cells, place the income gure for each of these months.
3. Label this area Actual Data.
4. In another section of the worksheet, type the numbers 13 through 18 in a
column to represent the upcoming 6 months.
5. In the column adjacent to the projected month numbers, select the six
adjacent cells (empty at present) by dragging over them.
6. Type =TREND( to start the function entry.
7. Drag the mouse over the range of known y values or type the range
address.
The known y values are the income gures you typed in Step 2.
8. Type a comma (,).
9. Drag the mouse over the range of known x values or type the range
address.
The known x values are the numbers 1 through 12 you typed in Step 1.
10. Type a comma (,).
11. Drag the mouse over the list of month numbers for which you want
projections (the numbers 13 through 18).
These are the new x values.
12. Type ).
13. Press Ctrl+Shift+Enter to complete the formula.
CHAPTER 11 Rolling the Dice onPredictions andProbability 223
When you’ve completed these steps, you see the projected income gures, calcu-
lated by the TREND function, displayed in the worksheet. An example is shown in
Figure11-6. There’s no assurance you’ll have this income— but it may be even
higher! You can always hope for the best.
GROWTH
The GROWTH function is like TREND in that it uses existing data to predict y val-
ues for a set of x values. It’s dierent in that it’s designed for use with data that
ts an exponential model. The function takes four arguments:
»
The rst argument is a range or array containing the known y values.
»
The second argument is a range or array containing the known x values.
»
The third argument is a range or array containing the x values for which you
want to calculate predicted y values.
»
The fourth value is omitted or TRUE if you want the constant b calculated
normally. If this argument is FALSE, b is forced to 1. You won’t use FALSE
except in special situations.
The number of known x and known y values must be the same for the GROWTH
function; otherwise, an error occurs. As you’d expect, GROWTH is an array for-
mula and must be typed accordingly.
To use the GROWTH function, follow these steps. (Note: These steps assume that
you have a worksheet that already contains known x and y values that t the expo-
nential model.)
FIGURE11-6:
Using the TREND
function to
calculate
predictions for an
array.
224 PART 3 Solving with Statistics
1. Type the x values for which you want to predict y values in a column of
the worksheet.
2. Select a range of cells in a column that has the same number of rows as
the x values you typed in Step 1.
Often, this range is in the column next to the x values, but it doesn’t have to be.
3. Type =GROWTH( to start the function entry.
4. Drag the mouse over the range containing the known y values or type the
range address.
5. Type a comma (,).
6. Drag the mouse over the range containing the known x values or type the
range address.
7. Type a comma (,).
8. Drag the mouse over the range containing the x values for which you
want to predict y values or type the range address.
9. Type ).
10. Press Ctrl+Shift+Enter to complete the formula.
Figure11-7 shows an example of using the GROWTH function to forecast expo-
nential data. Columns A and B contain the known data, and the range D10:D19
contains the x values for which predictions are desired. The GROWTH array for-
mula was typed in E10:E19. The chart shows a scatter plot of the actual data, up to
x = 40, and the projected data for x values above 40. You can see how the projected
data continues the exponential curves that are t by the actual data.
FIGURE11-7:
Demonstrating
use of the
GROWTH function
to project
exponential data.
CHAPTER 11 Rolling the Dice onPredictions andProbability 225
Using NORM.DIST and POISSON.DIST
toDetermine Probabilities
You can get a good introduction to the normal distribution in Chapter9. To dene
it briey, a normal distribution is characterized by its mean (the value in the mid-
dle of the distribution) and by its standard deviation (the extent to which values
spread out on either side of the mean). The normal distribution is a continuous
distribution, which means that x values can be fractional and aren’t restricted to
integers. The normal distribution has a lot of uses because so many processes,
both natural and human, follow it.
NORM.DIST
The word normal in this context doesn’t mean “good” or “okay,” and a distribu-
tion that is not normal is not necessarily awed in some way. Normal is used sim-
ply to mean “typical” or “common.”
Excel provides the NORM.DIST function for calculating probabilities from a nor-
mal distribution. The function takes four arguments:
»
The rst argument is the value for which you want to calculate a probability.
»
The second argument is the mean of the normal distribution.
»
The third argument is the standard deviation of the normal distribution.
»
The fourth argument is TRUE if you want the cumulative probability and FALSE
if you want the noncumulative probability.
A cumulative probability is the chance of getting any value between 0 and the speci-
ed value. A noncumulative probability is the chance of getting exactly the specied
value.
Normal distributions come into play for a wide variety of measurements. Exam-
ples include blood pressure, atmospheric carbon-dioxide levels, wave height, leaf
size, and oven temperature. If you know the mean and standard deviation of a
distribution, you can use NORM.DIST to calculate related probabilities.
Here’s an example: Your rm manufactures hardware, and a customer wants to
buy a large quantity of 50mm bolts. Due to the manufacturing process, the length
of bolts varies slightly. The customer will place the order only if at least 95 percent
of the bolts are between 49.9mm and 50.1mm. Measuring each one isn’t practical,
but previous data show that the distribution of bolt lengths is a normal
226 PART 3 Solving with Statistics
distribution with a mean of 50 and a standard deviation of 0.05. You can use Excel
and the NORM.DIST function to answer the question. Here’s the plan:
1. Use the NORM.DIST function to determine the cumulative probability of
a bolt’s being at least 50.1mm long.
2. Use the NORM.DIST function to determine the cumulative probability of
a bolt’s being at least 49.9mm long.
3. Subtract the second value from the rst to get the probability that a bolt
will be between 49.9mm and 50.1mm long.
Here are the steps to follow:
1. In a new worksheet, type the values for the mean, standard deviation,
upper limit, and lower limit in separate cells.
Optionally, add adjoining labels to identify the cells.
2. In another cell, type =NORM.DIST( to start the function entry.
3. Click the cell containing the lower limit value (49.9) or type the cell
address.
4. Type a comma (,).
5. Click the cell containing the mean or type the cell address.
6. Type a comma (,).
7. Click the cell containing the standard deviation or type the cell address.
8. Type a comma (,).
9. Type TRUE).
10. Press Enter to complete the function.
This cell displays the probability of a bolt’s being less than or equal to the lower
limit.
11. In another cell, type =NORMDIST( to start the function entry.
12. Click the cell containing the upper-limit value (50.1) or type the cell
address.
13. Repeat steps 4–10.
This cell displays the probability of a bolt’s being less than or equal to the
upper limit.
14. In another cell, type a formula that subtracts the lower-limit probability
from the upper-limit probability.
This cell displays the probability that a bolt will be within the specied limits.
CHAPTER 11 Rolling the Dice onPredictions andProbability 227
Figure11-8 shows a worksheet that was created to solve this problem. You can see
from cell B8 that the answer is 0.9545. In other words, 95.45 percent of your bolts
fall in the prescribed limits, and you can accept the customer’s order. Note in this
worksheet that the formulas in cells B6:B8 are presented in the adjacent cells so
you can see what they look like.
POISSON.DIST
Poisson is another kind of distribution used in many areas of statistics. Its most
common use is to model the number of events taking place in a specied time
period. Suppose that you’re modeling the number of employees calling in sick
each day or the number of defective items produced at your factory each week. In
these cases, the Poisson distribution is appropriate.
The Poisson distribution is useful for analyzing rare events. What does rare mean?
People calling in sick at work is hardly a rare event, but a specic number of
people calling in sick is rare, at least statistically speaking. Situations to which
Poisson is applicable include numbers of car accidents, counts of customers arriv-
ing, and manufacturing defects. One way to express it is that the events are indi-
vidually rare, but there are many opportunities for them to happen.
The Poisson distribution is a discrete distribution. This means that the x values in
the distribution can only take on specied, discrete values such as x = 1, 2, 3, 4, 5,
and so on. This is dierent from the normal distribution, which is a continuous
distribution in which x values can take any value (x = 0.034, 1.2365, and so on).
The discrete nature of the Poisson distribution is suited to the kinds of data you
use it with. For example, with employees calling in sick, you may have 1, 5, or 8 on
a given day, but certainly not 1.45, 7.2, or 9.15!
Figure11-9 shows a Poisson distribution that has a mean of 20. Values on the
x-axis are number of occurrences (of whatever you’re studying), and values on the
y-axis are probabilities. You can use this distribution to determine the probability
FIGURE11-8:
Using the NORM.
DIST function to
calculate
probabilities.
228 PART 3 Solving with Statistics
of a specic number of occurrences happening. For example, this chart tells you
that the probability of having exactly 15 occurrences is approximately 0.05
(5percent).
The Poisson distribution is a discrete distribution and is used only with data that
takes on discrete (integer) values, such as counting items.
A Poisson distribution is not always symmetrical, like the one shown in
Figure11-9. Negative x values make no sense in a Poisson distribution. After all,
you can’t have fewer than zero people calling in sick! If the mean is a small value,
the distribution will be skewed, as shown in Figure11-10 for a Poisson distribu-
tion with a mean of 4.
Excel’s POISSON.DIST function lets you calculate the probability that a specied
number of events will occur. All you need to know is the mean of the distribution.
This function can calculate the probability two ways:
FIGURE11-9:
A Poisson
distribution with
a mean of 20.
FIGURE11-10:
A Poisson
distribution with
a mean of 4.
CHAPTER 11 Rolling the Dice onPredictions andProbability 229
»
Cumulative: The probability that between 0 and x events will occur
»
Noncumulative: The probability that exactly x events will occur
The two Poisson graphs shown earlier in this chapter are for noncumulative
probabilities. Figure11-11 shows the cumulative Poisson distribution correspond-
ing to Figure11-9. You can see from this chart that the cumulative probability of
15events— the probability that 15 or fewer events will occur— is about 0.15.
What if you want to calculate the probability that more than x events will occur?
Simple! Just calculate the cumulative probability for x and subtract the result
from 1.
The POISSON.DIST function takes three arguments:
»
The rst argument is the number of events for which you want to calculate
the probability. This must be an integer value greater than 0.
»
The second argument is the mean of the Poisson distribution to use. This too
must be an integer value greater than 0.
»
The third argument is TRUE if you want the cumulative probability and FALSE
if you want the noncumulative probability.
Suppose that you’re the manager of a factory that makes brake shoes. Your district
manager has announced an incentive: You’ll receive a bonus for each day that the
number of defective shoes is less than 20. How many days a month will you meet
FIGURE11-11:
A cumulative
Poisson
distribution with
a mean of 20.
230 PART 3 Solving with Statistics
this goal, knowing that the average number of defective brake shoes is 25 per day?
Here are the steps to follow:
1. In a new worksheet, type the average number of defects per day (25) in
acell.
If desired, type an adjacent label to identify the cell.
2. In the cell below, type =POISSON.DIST( to start the function entry.
3. Type the value 20.
4. Type a comma (,).
5. Click the cell where you typed the average defects per day or type its cell
address.
6. Type a comma (,).
7. Type TRUE).
8. Press Enter to complete the formula.
9. If desired, type a label in an adjacent cell to identify this as the probabil-
ity of 20 or fewer defects.
10. In the cell below, type a formula that multiplies the number of working
days per month (22) by the result just calculated with the POISSON.DIST
function.
In your worksheet, this formula is =22*B3, typed in cell B4.
11. If desired, type a label in an adjacent cell to identify this as the number of
days per month you can expect to have 20 or fewer defects.
The nished worksheet is shown in Figure11-12. In this example, I have format-
ted cells B3:B4 with two decimal places. You can see that with an average of
25defects per day, you can expect to earn a bonus 4 days a month.
FIGURE11-12:
Using the
POISSON.DIST
function to
calculate a
cumulative
probability.
4
Dancing
with Data
IN THIS PART ...
Master dates.
Calculate time.
Look up data and become logical.
Discover information about your data and your
computer system.
Test-drive the text functions.
Dig into data with the database functions.
CHAPTER 12 Dressing Up for Date Functions 233
Chapter12
Dressing Up for Date
Functions
Often, when working with Excel, you need to manage dates. Perhaps you
have a list of dates when you visited a client and need to count how many
times you were there in September. On the other hand, maybe you are
tracking a project over a few months and want to know how many days are in
between the milestones.
Excel has a number of useful Date functions to make your work easier! This chap-
ter explains how Excel handles dates, how to compare and subtract dates, how to
work with parts of a date (such as the month or year), and even how to count the
number of days between two dates. You can always reference the current data
from your computer’s clock and use it in a calculation; I show you how.
Understanding How Excel Handles Dates
Imagine that on January 1, 1900, you started counting by ones, each day adding
one more to the total. This is just how Excel thinks of dates. January 1, 1900, is
one; January 2, 1900, is two; and so on. We’ll always remember 25,404 as the day
man rst walked on the moon, and 36,892 as the start of the new millennium!
IN THIS CHAPTER
»
Handling and formatting dates
»
Working with days, months, and
years
»
Getting the value of today
»
Determining the day of the week
»
Calculating the time between dates
234 PART 4 Dancing with Data
The millennium actually started on January 1, 2001. The year 2000 is the last year
of the 20th century. Representing dates as a serial number— specically, the
number of days between January 1, 1900, and the date in question— may seem
odd, but there are very good reasons for it. Excel can handle dates from January 1,
1900, to December 31, 9999. Using the serial numbering system, that’s 1 through
2,958,465!
Because Excel represents dates in this way, it can work with dates in the same
manner as numbers. For example, you can subtract one date from another to nd
out how many days are between them. Likewise, you can add 14 to today’s date to
get a date two weeks in the future. This trick is very useful, but people are used to
seeing dates represented in traditional formats, not as numbers. Fortunately,
Excel uses date serial numbers only behind the scenes, and what you see in your
workbook are dates in the standard date formats such as Jan 20, 2021 and 1/20/21.
In Excel for the Mac, the serial numbering system begins on January 1, 1904.
The way years are handled requires special mention. When a year is fully dis-
played in 4 digits, such as 2021, there is no ambiguity. However, when a date is
written in a shorthand style, such as in 3/1/25, it isn’t clear what the year is. It
could be 2025 or it could be 1925. Suppose that 3/1/25 is a shorthand entry for
someone’s birthday. On March 1, 2028, they’re either 3 years old or 103 years old.
In those countries that write dates as dd/mm/yy, this would be March 1, 1925, or
March 3, 2025.
Excel and the Windows operating system have a default way of interpreting short-
hand years. Windows has a setting in the Customize Regional Options dialog box
located in the Control Panel. This setting guides how Excel interprets years. If the
setting is 1950 through 2049, 3/1/25 indicates the year 2025, but 3/1/45 indicates
the year 1945, not 2045. Figure12-1 shows this setting.
Here’s how to open and set it:
1. Use the Windows search feature to nd and open Control Panel.
2. Select Clock and Region.
3. Select Region.
The Region dialog box opens.
4. Select the Formats tab.
5. Click the Additional Settings button.
The Customize Format dialog box opens.
6. Select the Date tab.
CHAPTER 12 Dressing Up for Date Functions 235
7. In the Calendar section, select a 4-digit ending year (such as 2049) to
indicate the latest year that will be used when interpreting a 2-digit year.
8. Click Apply and then click OK to close each dialog box.
To ensure full accuracy when working with dates, always type the full 4 digits for
the year.
Formatting Dates
When you work with dates, you probably need to format cells in your worksheet.
It’s great that Excel tells you that June 1, 2021, is serially represented as 44348,
but you probably don’t want that in a report. To format dates, you use the Format
Cells dialog box, as shown in Figure12-2.
To format the currently selected cells as dates, follow these steps:
1. If it’s not already displayed, select the Home tab at the top of the Excel
screen.
2. Click the small arrow at the bottom-right corner of the Number section.
The Format Cells dialog box appears, revealing the Number tab.
FIGURE12-1:
Setting how years
are interpreted in
the Customize
Format
dialog box.
236 PART 4 Dancing with Data
3. Select Date from the Category list.
4. Select an appropriate format from the Type list.
Now you can turn the useful but pesky serial dates into a user-friendly format.
When you type a date in a cell using one of the standard date formats, Excel rec-
ognizes it as a date and automatically assigns a Date format to the cell. You may
want to use the Number tab in the Format Cells dialog box to assign a dierent
Date format.
Making a Date with DATE
You can use the DATE function to create a complete date from separate year,
month, and day information. The DATE function can be useful because dates don’t
always appear as, well, dates, in a worksheet. You may have a column of values
between 1 and 12 that represents the month and another column of values between
1 and 31 for the day of the month. A third column may hold years— in either
2-digit shorthand or the full 4 digits.
The DATE function combines individual day, month, and year components into a
single usable date. This makes using and referencing dates in your worksheet
easy. Follow along to use the DATE function:
FIGURE12-2:
Using the Format
Cells dialog box
to control how
dates are
displayed.
CHAPTER 12 Dressing Up for Date Functions 237
1. Click the cell where you want the results displayed.
2. Type =DATE( to begin the function entry.
3. Click the cell that has the year.
4. Type a comma (,).
5. Click the cell that has the number (1–12) that represents the month.
6. Type a comma (,).
7. Click the cell that has the number (1–31) that represents the day of the
month.
8. Type ) and press Enter.
Figure12-3 displays a fourth column of dates that were created by using DATE and
the values from the rst three columns. The fourth column of dates has been for-
matted so the dates are displayed in a standard format, not as a raw date serial
number.
DATE provides some extra exibility with the month number. Negative month
numbers are subtracted from the specied year. For example, the function
=DATE(2021,-5,15) returns the date July 15, 2020, because July 2020 is 5 months
before the rst month of 2021. Numbers greater than 12 work the same way.
=DATE(2021,15,1) returns March 1, 2022, because March 2022 is 15 months after
the rst month of 2021.
FIGURE12-3:
Using the DATE
function to
assemble a date
from separate
month, day, and
year values.
238 PART 4 Dancing with Data
Day numbers work the same way. Negative day numbers are subtracted from the
rst of the specied month, and numbers that are greater than the last day of
the specied month wrap into later months. Thus, =DATE(2021,2,30) returns
March 2, 2021, because February does not have 30 days. Likewise, =DATE(2021,2,40)
returns March 12, 2021.
Breaking a Date with DAY, MONTH,
and YEAR
That which can be put together can also be taken apart. In the preceding section,
I show you how to use the DATE function to create a date from separate year,
month, and day data. In this section, you nd out how to do the reverse: Split a
date into individual year, month, and day components by using the YEAR, MONTH,
and DAY functions, respectively. In Figure12-4, the dates in column A are split
apart by day, month, and year, respectively, in columns B, C, and D.
FIGURE12-4:
Splitting apart a
date with the
DAY, MONTH,
and YEAR
functions.
CHAPTER 12 Dressing Up for Date Functions 239
Isolating the day
Isolating the day part of a date is useful when just the day but not the month or
year is relevant. Suppose that you own a store and want to gure out whether
more customers come to shop in the rst half or the second half of the month.
You’re interested in this trend over several months. So the task may be to average
the number of sales by the day of the month only.
The DAY function is useful for this because you can use it to return just the day for
a lengthy list of dates. Then you can examine results by the day only.
Here’s how you use the DAY function:
1. Position the pointer in the cell where you want the results displayed.
2. Type =DAY( to begin the function entry.
3. Click the cell that has the date.
4. Type ) and press Enter.
Excel returns a number between 1 and 31.
Figure12-5 shows how the DAY function can be used to analyze customer activity.
Column A contains a full year’s sequential dates (most of which are not visible in
the gure). In column B, the day part of each date has been isolated. Column C
shows the customer trac for each day.
This is all the information you need to analyze whether there is a dierence in the
amount of customer trac between the rst half and second half of the month.
FIGURE12-5:
Using the DAY
function to
analyze customer
activity.
240 PART 4 Dancing with Data
Cells E4 and E10 show the average daily customer trac for the rst half and
second half of the month, respectively. The value for the rst half of the month
was obtained by adding all the customer values for day values in the range 1 to
15 and then dividing by the total number of days. The value for the second half of
the month was done the same way, using day values in the range 16 to 31.
The day parts of the dates, in column B, were key to these calculations:
»
In cell E4, the calculation is =SUMIF(B2:B366,"<16",C2:C366)/
COUNTIF(B2:B366"<16").
»
In cell E10, the calculation is =SUMIF(B2:B366,">15",C2:C366)/
COUNTIF(B2:B366,">15").
The SUMIF function is discussed in Chapter8. The COUNTIF function is discussed
in Chapter9.
The DAY function has been instrumental in showing that more customers visit the
ctitious store in the second half of the month. This type of information is great
for helping a store owner plan sta assignments, sales specials, and so on.
Isolating the month
Isolating the month part of a date is useful when just the month, but not the day
or year, is relevant. For example, you may have a list of dates on which more than
ve of your employees call in sick and need to determine whether this event is
more common in certain months than others.
You could sort the dates and then count the number for each month. That would
be easy enough, but sorting may not be an option based on other requirements.
Besides, why manually count when you have, right in front of you, one of the all-
time greatest counting software programs ever made?
Figure12-6 shows a worksheet in which the MONTH function has extracted the
numeric month value (1–12) into column B from the dates in column A.Cell B2
contains the formula =MONTH(A2) and so on down the column. Columns C and D
contain a summary of dates per month. The formula used in cell D3 is
=COUNTIF($B$2:$B$260,1).
This counts the number of dates in which the month value is 1— in other words,
January. Cells D4 through D14 contain similar formulas for month values 2 through
12. The gure’s data plot makes it clear that calling in sick is more prevalent in
December and January. See Chapter9 for information on the COUNTIF function.
CHAPTER 12 Dressing Up for Date Functions 241
Use the MONTH function this way:
1. Click the cell where you want the results displayed.
2. Type =MONTH( to begin the function entry.
3. Click the cell that has the date.
4. Type ) and press Enter.
Excel returns a number between 1 and 12.
Isolating the year
Isolating the year part of a date is useful when only the year, but not the day or
month, is relevant. In practice, this is less used than the DAY or MONTH functions
because date data is often— though not always— from the same year.
Follow these steps to use the YEAR function:
1. Click the cell where you want the results displayed.
2. Type =YEAR( to begin the function entry.
3. Click the cell that has the date.
4. Type ) and press Enter.
Excel returns the 4-digit year.
FIGURE12-6:
Using the MONTH
function to count
the number of
dates falling in
each month.
242 PART 4 Dancing with Data
Converting a Date from Text
You may have data in your worksheet that looks like a date but is not represented
as an Excel date value. For example, if you type 01-24-21in a cell, Excel would
have no way of knowing whether this is January 24, 2021, or the code for your
combination lock. If it looks like a date, you can use the DATEVALUE function to
convert it to an Excel date value.
In practice, any standard date format typed into a cell is recognized by Excel as a
date and converted accordingly. However, there may be cases such as when text
dates are imported from an external data source or data is copied and pasted into
Excel for which you need DATEVALUE.
Why not type dates as text data? Although they may look ne, you can’t use them
for any of Excel’s powerful date calculations without rst converting them to date
values.
The DATEVALUE function recognizes almost all commonly used ways that dates
are written. Here are some ways that you may type August 14, 2021:
»
8/14/21
»
14-Aug-2021
»
2021/08/14
DATEVALUE can convert these and several other date representations to a date
serial number.
After you’ve converted the dates to a date serial number, you can use the dates in
other date formulas or perform calculations with them as described in other parts
of this chapter.
To use the DATEVALUE function, follow these steps:
1. Click the cell where you want the date serial number located.
2. Type =DATEVALUE( to begin the function entry.
3. Click the cell that has the text format date.
4. Type ) and press Enter.
The result is a date serial number unless the cell where the result is displayed
has already been set to a date format.
CHAPTER 12 Dressing Up for Date Functions 243
Figure12-7 shows how some nonstandard dates in column A have been converted
to serial numbers with the DATEVALUE function in column B. Then column C
displays these serial numbers formatted as dates.
Do you notice something funny in Figure12-7? Normally, you aren’t able to type
a value such as the one in cell A4— 02-28-21— without losing the leading 0. The
cells in column A had been changed to the Text format. This format tells Excel to
leave your entry as is. The Text format is one of the choices in the Category list in
the Format Cells dialog box (refer to Figure12-2).
Note also that the text date in cell A8, Feb 9 22, could not be converted by DATEV-
ALUE, so the function returns the error message #VALUE#. Excel is great at rec-
ognizing dates, but I did not say it is perfect! In cases such as this, you have to
format the date another way so DATEVALUE can recognize it.
Finding Out What TODAY Is
When working in Excel, you often need to use the current date. Each time you
print a worksheet, for example, you may want the day’s date to show. The TODAY
function lls the bill perfectly. It simply returns the date from your computer’s
internal clock. To use the TODAY function, follow these steps:
1. Position the pointer in the cell where you want the result.
2. Type =TODAY().
3. Press Enter to end the function.
That’s it! You now have the date from your computer. If your computer’s clock is
not set correctly, don’t blame Excel. As with all dates in Excel, what you really end
up with is a serial number, but the Date formatting displays the date in a readable
fashion.
FIGURE12-7:
Converting dates
to their serial
equivalents with
the DATEVALUE
function.
244 PART 4 Dancing with Data
As with all functions in Excel, you can embed functions in other functions. For
example, if you need to know just the current date’s month, you can combine the
TODAY function with the MONTH function, like this:
=MONTH(TODAY())
Counting the days until your birthday
After a certain age, a lot of people wish their birthdays would not come around so
often, but if you still like birthdays, you can use Excel to keep track of how many
days are left until the next one. Typed in a cell, this formula tells you how many
days are left until your birthday (assuming that your next birthday is May 5,
2022):
=DATE(2022,5,5)-TODAY()
Use the DATE function to type the day, month, and year of your next birthday.
This prevents Excel from interpreting a shorthand entry, such as 5/5/2022, as a
mathematical operation on its own.
If the formula were =5/5/2022–TODAY(), Excel would calculate an incorrect
answer because the formula eectively says, “Divide 5 by 5, then divide that result
by 2022, then subtract the serial number of today’s date.” The answer would be
incorrect.
Using the DATE function to represent dates in which a mathematical operation is
performed is a good idea.
Counting your age in days
When your birthday nally rolls around, someone may ask how old you are. Maybe
you’d rather not say. Here’s a way to respond, but in a way that leaves some
doubt: Answer by saying how old you are in days!
Excel can help you gure this out. All you have to do is count the number of days
between your birth date and the current date. A simple formula tells you this:
=TODAY()-DATE(birth year,birth month,birth day)
Here’s an example, assuming that your birthday is March 18, 1976:
=TODAY()-DATE(1976,3,18)
CHAPTER 12 Dressing Up for Date Functions 245
Determining the Day of the Week
The Beatles recorded a song called “Eight Days a Week,” but for the rest of us,
sevendays is the norm. The WEEKDAY function helps you gure out which day of
the week a date falls on. Now you can gure out whether your next birthday falls
on a Friday. Or you can make sure that a planned business meeting does not fall
on a weekend.
Here is how you use the WEEKDAY function:
1. Click the cell where you want the results displayed.
2. Type =WEEKDAY( to begin the function entry.
3. Click the cell that has the date for which you want to nd the weekday.
4. Type ) and press Enter.
WEEKDAY returns a number between 1 and 7. Table12-1 shows what the
returned number means.
Don’t confuse the returned numbers with actual dates! Just because Table12-1
shows a value of 4 indicating Wednesday doesn’t mean that the fourth day of a
month is a Wednesday. The values of the returned numbers are also a bit confus-
ing because most people consider Monday, not Sunday, to be the rst day of the
week. You can go argue the point with Microsoft, if you like! Better yet, you can
include a second, optional, argument that tells WEEKDAY to return 1 for Monday,
2 for Tuesday, and so on:
=WEEKDAY(A1,2)
TABLE12-1 WEEKDAY Returned Values
Returned Value Weekday
1Sunday
2Monday
3Tuesday
4Wednesday
5Thursday
6Friday
7Saturday
246 PART 4 Dancing with Data
The numbers 1 through 7, returned from the WEEKDAY function, are not the same
as the rst through seventh of the month.
The WEEKDAY function lets you extract interesting information from date-related
data. For example, maybe you’re on a diet, and you’re keeping a tally of how many
calories you consume each day for a month. Then you start wondering “On which
days do I eat the most?” Figure12-8 shows a worksheet that calculates the aver-
age calories consumed on each day of the week over a month’s time. A glance at
the results shows that Saturdays and Sundays are not your high-calorie-
consumption days; it’s Wednesday and Thursday that you have to watch out for.
Working with Workdays
Most weeks have 5 workdays— Monday through Friday— and 2 weekend days.
(I know; some weeks seem to have 20 workdays, but that’s just your imagination!)
Excel has two functions that let you perform workday-related calculations.
Determining workdays in a range of dates
The NETWORKDAYS function tells you how many working days are in a range of
dates. Do you ever sit at your desk and stare at the calendar, trying to count how
many working days are left in the year? Excel can answer this vital question
for you!
FIGURE12-8:
Using WEEKDAY
tells you which
day of the week a
date falls on.
CHAPTER 12 Dressing Up for Date Functions 247
NETWORKDAYS counts the number of days, omitting Saturdays and Sundays, in a
range of dates that you supply. You can add a list of dates that should not be
counted, if you want. This optional list is where you can put holidays, vacation
time, and so on.
Figure 12-9 shows an example using NETWORKDAYS. Cells C3 and C4 show
the start and end dates, respectively. In this example, the start date is provided by
the TODAY function. Therefore, the result always reects a count that starts
from the current date. The end date is the last day of the year. The function in cell
C6 is =NETWORKDAYS(C3,C4,C10:C23).
The function includes the cells that have the start and end dates. Then there is a
range of cells: C10 through C23. These cells have dates that should not be counted
in the total of workdays: holidays and vacations. You can put anything in these
cells, but they do have to be Excel dates. If a date specied in this list falls on a
workday, NETWORKDAYS does not count it. If it falls on a weekend, it would not
be counted anyway, so it is ignored.
To use NETWORKDAYS, follow these steps:
1. Click the cell where you want the results displayed.
2. Type =NETWORKDAYS( to begin the function entry.
FIGURE12-9:
Counting
workdays with
NETWORKDAYS.
248 PART 4 Dancing with Data
3. Click the cell that has the start date for the range of dates to be counted.
4. Type a comma (,).
5. Click the cell that has the end date for the range of dates to be counted.
If you want to add a list of dates to exclude, continue to steps 6 and 7; other-
wise, go to Step 8.
6. Type a comma (,).
7. Click and drag the pointer over the cells that have the dates to exclude.
8. Type ) and press Enter.
The result is a count of days, between the start and end dates, that do not fall
on Saturday or Sunday and are not in an optional list of exclusion dates.
Workdays in the future
Sometimes, you are given a deadline (“Have that back to me in 20 working days”),
or you give it to someone else. Fine, but what is the date 20 working days from
now? The WORKDAY function comes to the rescue. You specify a start date, the
number of working days, and an optional list of holidays that are not to be counted
as working days. (This list works just the same as for the NETWORKDAYS func-
tion, discussed in the previous section.)
To use WORKDAYS, follow these steps:
1. Click the cell where you want the results displayed.
2. Type =WORKDAY( to begin the function entry.
3. Click the cell that has the start date for the calculation.
4. Type a comma (,).
5. Click the cell that has the number of workdays or type the number
directly in the formula.
If you want to add a list of dates to exclude in the count, continue to steps 6
and 7; otherwise, go to Step 8.
6. Type a comma (,).
7. Click and drag the pointer over the cells that have the dates to be
excluded.
8. Type ) and press Enter.
The result is a date that is the specied number of workdays from the start
date, not counting dates in the optional list of exclusion dates.
CHAPTER 12 Dressing Up for Date Functions 249
Calculating Time Between Two Dates with
the DATEDIF Function
Excel provides the DATEDIF function to calculate the number of days, months, or
years between two dates. This is an undocumented function; that is, you won’t see
it in the Insert Function dialog box. Why is it not in the Insert Function dialog box?
Beats me— but it sure can be useful! Impress your friends and coworkers. The
only thing you have to do is remember how to type it. For that, you may want to
keep this book handy to look it up.
DATEDIF takes three arguments:
»
Start date
»
End date
»
Interval
The interval argument tells the function what type of result to return, summa-
rized in Table12-2.
TABLE12-2 Settings for the Interval Argument of DATEDIF
Value What It Means Comment
"d" Days The count of inclusive days from the start date through the end date.
"m" Months The count of complete months between the dates. Only those months that
fully occur between the dates are counted. For example, if the rst date
starts after the rst of the month, that rst month is not included in the
count. For the end date, even when it is the last day of the month, that
month is not counted. See Figure12-10 for an example.
"y" Years The count of complete years between the dates. Only those years that fully
occur between the dates are counted. For example, if the rst date starts
later than January 1, that rst year is not included in the count. For the end
date, even when it is December 31, that year is not counted. See Figure12-10
for an example.
"yd" Days excluding
years
The count of inclusive days from the start date through the end date, but as
if the two dates are in the same year. The year is ignored.
"ym" Months excluding
years
The count of complete months between the dates, but as if the two dates
are in the same year. The year is ignored.
"md" Days excluding
months and years
The count of inclusive days from the start date through the end date, but as
if the two dates are in the same month and year. The month and year are
ignored.
250 PART 4 Dancing with Data
Figure12-10 shows some examples of using DATEDIF.Column A has start dates.
Column B has end dates. Columns C through H contain formulas with DATE-
DIF.The DATEDIF function uses the start and end dates on each given row, and
the interval is labeled at the top of each column, C through H.
Here’s how to use DATEDIF:
1. Click the cell where you want the results to appear.
2. Type =DATEDIF( to begin the function entry.
3. Click a cell where you have a date or type its address.
4. Type a comma (,).
5. Click a cell where you want another date.
This date must be the same or greater than the rst date from Step 3;
otherwise, you get an error.
6. Type a comma (,).
7. Type an interval.
Refer to Table12-2 for the list of intervals that you can use with the function.
Make sure that the interval is enclosed in double quotes.
8. Type a ) and press Enter.
FIGURE12-10:
Counting days,
months, and
years with
DATEDIF.
CHAPTER 13 Keeping Well-Timed Functions 251
Chapter13
Keeping Well-Timed
Functions
Excel has a handful of superb functions for working with times and perform-
ing calculations on time values. You can analyze data to the hour, minute, or
second. And Excel helps you get this done in a NewYork minute!
Understanding How Excel Handles Time
In Chapter12, I explain how Excel uses a serial number system to work with dates.
Well, guess what? The same system is used to work with time. The key dierence
is that although dates are represented by the integer portion of a serial number,
time is represented by the decimal portion.
What does this mean? Consider this: 43466. That is the serial number representa-
tion for January 1, 2019. Notice, though, that there is no indication of the time of
day. The assumed time is 12 a.m. (midnight), the start of the day. You can, how-
ever, represent specic times if needed.
Excel uses the decimal side of the serial number to represent time as a fraction of
the 24-hour day. Thus, 12 p.m. (noon) is 0.5, and 6 p.m. is 0.75. Table13-1 shows
IN THIS CHAPTER
»
Handling time
»
Formatting time values
»
Working with hours, minutes, and
seconds
»
Getting the current time
»
Calculating elapsed time
252 PART 4 Dancing with Data
some more examples and reveals how dates and time information are combined in
a single serial number.
Time is represented in a decimal value— up to ve digits to the right of the deci-
mal point. A value of 0 is the equivalent of 12 a.m. A value of .5 is the equivalent of
12 p.m.— the midpoint of the day. The value of .99931 is the same as the 23rd
hour and the start of the 59th minute. A value of .99999 is the same as the 23rd
hour, the 59th minute, and the 59th second— in other words, 1 second before the
start of the next day.
Can you represent time without a date? You bet! Use a value less than 1 for this
purpose. For example, the serial number 0.75 represents 6 p.m. with no date
specied.
Representing time as a serial number provides the same advantages as it does for
dates: the ability to add and subtract times. For example, given a date/time serial
number, you can create the serial number for the date/time one and a half days
later by adding 1.5 to it.
Formatting Time
When you work with time values, you probably need to format cells in your work-
sheet so the times display in a standard format that people will understand. The
decimal numbers don’t make sense to us human folk. To format time, you use the
Number tab of the Format Cells dialog box, as shown in Figure13-1.
TABLE13-1 How Excel Represents Time
Date and Time Serial Format
January 1, 2019 12:00 a.m. 43466
January 1, 2019 12:01 a.m. 43466.00069
January 1, 2019 10:00 a.m. 43466.41667
January 1, 2019 12:00 p.m. 43466.5
January 1, 2019 4:30 p.m. 43466.6875
January 1, 2019 10:00 p.m. 43466.91667
January 1, 2019 11:59 p.m. 43466.99931
CHAPTER 13 Keeping Well-Timed Functions 253
To format time, follow these steps:
1. If it’s not already displayed, select the Home tab at the top of the Excel
screen.
2. Click the small arrow in the bottom-right corner of the Number section.
The Format Cells dialog box appears, with the Number tab displayed.
3. Select Time in the Category list.
4. Select an appropriate format in the Type list.
You can display time in several ways. Excel can format time so that hours in a day
range from 1 a.m. to 12 a.m. and then 1 p.m. to 12 p.m. Alternatively, the hour can
be between 0 and 23, with values 13 through 23 representing 1 p.m. through 11 p.m.
The latter system, known to some as military time or 24-hour time, is commonly
used in computer systems.
Note that Excel stores a date and time together in a single serial number. There-
fore, some of the formatting options in the time and date categories display a
complete date and time.
FIGURE13-1:
Using the Format
Cells dialog box
to specify how
time values are
displayed.
254 PART 4 Dancing with Data
Keeping TIME
You can use the TIME function to combine hours, minutes, and seconds into a
single usable value. Figuring out the serial number representation of a particular
moment in time isn’t easy. Luckily, the TIME function does this for you. You pro-
vide an hour, minute, and second, and TIME tells you the serial value. To do this,
follow these steps:
1. Select the cell where you want the result displayed.
2. Type =TIME( to begin the function entry.
3. Click the cell that has the hour (0–23) or enter such a value.
4. Type a comma (,).
5. Click the cell that has the minute (0–59) or enter such a value.
6. Type a comma (,).
7. Click the cell that has the second (0–59) or enter such a value.
8. Type ) and press Enter.
The result is a decimal serial number, or a readable time if the cell is formatted
properly.
You should be aware that the minute and second values “wrap.” A value of 60 or
greater for seconds wraps to the next minute. For example, 75 seconds is inter-
preted as 1 minute 15 seconds. Likewise, a minute value of 90 is interpreted as
1 hour 30 minutes. Hours wrap, too. An hour value of 26 is interpreted as 2 a.m.
Converting Text to Time with TIMEVALUE
If you enter a time in a standard format in a cell, Excel recognizes it as a time. It
is converted to a serial number, and the cell is assigned the default time format. If
you are pasting or importing data from another application, you may encounter
times in text format, such as 2:28 PM.You can convert these to a time serial num-
ber by using the TIMEVALUE function. Here’s how:
1. Select the cell where you want the result displayed.
2. Type =TIMEVALUE( to begin the function entry.
3. Click the cell that contains the time in text format.
4. Type ) and press Enter.
CHAPTER 13 Keeping Well-Timed Functions 255
TIMEVALUE works just with text. If the TIMEVALUE function returns the error
code #VALUE#, it probably means one of two things:
»
The time is in a text format that Excel does not recognize, such as 2:28PM
(no space before PM) instead of 2:28 PM.
»
The time is not actually in text format but is an Excel time serial number
formatted to look that way. Change the cell format to General to check.
Deconstructing Time with HOUR,
MINUTE, and SECOND
Any moment in time really is a combination of an hour, a minute, and a second.
In the preceding section, I show you how the TIME function puts these three com-
ponents together. In this section, I show you how to break them apart by using the
HOUR, MINUTE, and SECOND functions. The worksheet in Figure13-2 shows a
date and time in several rows going down column A.The same dates and times are
shown in column B, with a dierent format. Columns C, D, and E show the hour,
minute, and second, respectively, from the values in column A.
Note that if the date/time serial number contains a date part, HOUR, MINUTE, and
SECOND ignore it; all they care about is the time part.
FIGURE13-2:
Splitting time with
the HOUR,
MINUTE, and
SECOND
functions.
256 PART 4 Dancing with Data
Isolating the hour
Extracting the hour from a time is useful in workbooks that tally hourly events.
Acommon use of this occurs in call centers. If you’ve ever responded to an info-
mercial or a pledge drive, you may realize that a group of workers wait for incom-
ing phone calls such as the one you made. (I hope you got a good bargain.)
Acommon metric in this type of business is the number of calls per hour.
Figure13-3 shows a worksheet that summarizes calls per hour. Calls have been
tracked for October 2012. The incoming call dates and times are listed in column
A.In column B, the hour of each call has been isolated with the HOUR function.
Columns D and E show a summary of calls per hour over the course of the month.
In Figure13-3, the values in column E are calculated by the COUNTIF function.
There is a COUNTIF for each hour from 10 a.m. through 11 p.m. Each COUNTIF
looks at the range of numbers in column B (the hours) and counts the values that
match the criteria. Each COUNTIF uses a dierent hour value for its criteria. Fol-
lowing is an example:
=COUNTIF($B$3:$B$1100,"=16")
Here is how to use the HOUR function:
1. Select the cell where you want the result displayed.
2. Type =HOUR( to begin the function entry.
FIGURE13-3:
Using the HOUR
function to
summarize
results.
CHAPTER 13 Keeping Well-Timed Functions 257
3. Click the cell that has the full time (or date/time) entry.
4. Type ) and press Enter.
Excel returns a number between 0 and 23.
Isolating the minute
Isolating the minute part of a time is necessary in workbooks that track activity
down to the minute. A timed test is a perfect example. Remember when the teacher
would yell, “Pencils down”?
Excel can easily calculate how long something takes by subtracting one time from
another. In the case of a test, the MINUTE function helps with the calculation
because how long something took in minutes is being gured out. Figure13-4
shows a list of times it took for students to take a test. All students started the test
at 10 a.m. Then, when each student nished, the time was noted. The test should
have taken a student no more than 15 minutes.
For each data row, column D contains a formula that subtracts the minute in the
end time, in column C, from the start time, in column B.This math operation is
embedded in an IF statement. If the result is 15 or less, Yes appears in column D;
otherwise, No appears.
=IF(MINUTE(C3)-MINUTE(B3)<=15,"Yes","No")
Like the HOUR function, the MINUTE function takes a single time or date/time
reference as its argument.
FIGURE13-4:
Calculating
minutes elapsed
with the MINUTE
function.
258 PART 4 Dancing with Data
Isolating the second
Isolating the second from a date value is useful in situations in which highly accu-
rate time calculations are needed. In practice, this isn’t a common requirement in
Excel worksheets.
Follow these steps to use the SECOND function:
1. Position the pointer in the cell where you want the results displayed.
2. Type =SECOND( to begin the function entry.
3. Click the cell that has the time value or enter a time value.
4. Type ) to end the function, and press Enter.
Finding the Time NOW
Sometimes when you’re working in Excel, you need to access the current time. For
example, you may be working on a client project and need to know how much time
you’ve spent on it. Use the NOW function when you rst open the workbook, and
use it again when you’re nished. Subtracting one value from the other provides
the elapsed time.
Here’s how to use the NOW function:
1. Select the cell where you want the result.
2. Type =NOW().
3. Press Enter to end the function.
You must take one additional step to make the preceding NOW time calculation
work. When you get the current time at the start, copy the value and then use
Paste Special to paste it back as a value. This strategy prevents the time from con-
stantly updating. You can also do this by selecting the cell, clicking the Formula
Bar, and then pressing F9.
NOW provides not just the current time, but also the current date. This is similar
to the TODAY function. TODAY returns the current date— without the current
time. NOW returns the full current date and time. See Chapter12 for more infor-
mation on the TODAY function.
CHAPTER 13 Keeping Well-Timed Functions 259
Calculating Elapsed Time Over Days
Each day has 24 hours. Multiplying 24 by 7 tells you that there are 168 hours in a
week. How many hours are in a month? This is not as easy to tell. A month may
have 28, 29, 30, or 31 days.
Counting elapsed time, in hours, could require a complex algorithm. Although
Excel has no single function for this task, you can combine a couple of functions
in a formula to get the answer. This is another benet of the fact that Excel rep-
resents date/time values as serial numbers. This makes it easy to calculate the
number of hours that have passed between two date/time values.
Figure13-5 shows a worksheet with start and end date/time values in two col-
umns. A third column shows the calculated number of elapsed hours for each
start/end pair.
In column A and column B are dates and times. These dates and times are really
just serial numbers with a decimal portion. Using the INT function, Excel counts
the dierence in days, even if the span pops over to a new year. Then it uses the
HOUR function to calculate the dierence of the decimal portion. The formula for
the rst row is
=(INT(B3)-INT(A3))*24+HOUR(B3)-HOUR(A3)
FIGURE13-5:
Calculating
elapsed time.
260 PART 4 Dancing with Data
Each successive row has the same formula in column C but with the cell references
pointed to the values on that row. The rst part of the formula calculates the dif-
ference in days and multiplies this by 24 for the total number of hours in the
number of days.
The trick is to correctly calculate the time between the start and end values. The
hour portion of both the start and end values is determined with the HOUR func-
tion; then one value is subtracted from the other. The result of this subtraction is
added to the precalculated number of hours from the count of days. Note that
minutes are ignored. Perhaps you can gure out how to modify the formula to
take seconds into account!
CHAPTER 14 Using Lookup, Logical, and Reference Functions 261
Chapter14
Using Lookup, Logical,
and Reference Functions
Decision, decisions! If one of your students gets an 88 on the test, is that a
B+ or is it an A? If your company’s new product earns at least $15 million
in revenue, how much of a bonus should you give to the team? Or do you
have to get to $20,000,000 before you do that? How does this aect the nancial
statements?
Excel cannot make decisions for you, but it can help you make better decisions.
Using functions, such as IF and CHOOSE, you can set up your worksheet to chart a
course through the possibilities. Hey, things could be worse! Were it not for Excel,
you might have to try the old Ouija-board technique.
Excel also can help you nd what you’re looking for. Looking for something in a
large, complex worksheet can seem like the old needle-in-a-haystack routine.
It’s okay to admit it. After all, it happens to the best of us! I’m here to help. In this
chapter, I show you a slew of functions that make it easy to look up information
that’s spread around the rows and columns.
IN THIS CHAPTER
»
Using IF to take a course of action
»
Returning a value with CHOOSE
»
Applying logic with AND, OR, and XOR
»
Finding where values are
»
Looking up values in a table
»
Matching data
262 PART 4 Dancing with Data
Testing on One Condition
The IF function is like the Swiss Army knife of Excel functions. Really, it is used in
many situations. Often, you can use it with other functions, which I do often in
this chapter. IF, structurally, is easy to understand. The function takes three
arguments:
»
A test that gives a true or false answer: For example, the test “Is the value
in cell A5 equal to the value in cell A8?” can have only one of two possible
answers, yes or no. In computer talk, that’s true or false. This is not a calcula-
tion, mind you, but a comparison.
»
The data to be returned by the IF function if the test is true.
»
The data to be returned by the IF function if the test is false.
Sounds easy enough. Table14-1 shows some examples.
An important aspect to note about using IF is that you can let the second . . .
nothing, which will return an empty string. The best way . . . to do this is to place
two double quote marks together with nothing in the middle. The result is that the
cell containing the IF function appears blank.
TABLE14-1 Using the IF Function
Function Comment
=IF(D10>D20,D10,D20) If the value in D10 is greater than the value in D20, the
value in D10 is returned because the test is true. If the
value in D10 is not greater than— that is, smaller or equal
to— the value in D20, the value in D20 is returned. If the
values in D10 and D20 are equal, the test returns false,
and the value in D20 is returned.
=IF(D10>D20,"Good
news!","Bad news!")
If the value in D10 is greater than the value in D20, the
text Good news! is returned. Otherwise, Bad news! is
returned.
=IF(D10>D20,"","Bad
news!")
If the value in D10 is greater than the value in D20, noth-
ing is returned. Otherwise, Bad news! is returned. Note
that the second argument is a pair of empty quotes.
=IF(D10>D20,"Good
news!","")
If the value in D10 is greater than the value in D20, Good
news! is returned. Otherwise, nothing is returned. Note
that the third argument is empty quotes.
CHAPTER 14 Using Lookup, Logical, and Reference Functions 263
IF, therefore, lets you set up two results to return: one for when the test is true
and another for when the test is false. Each result can be a number, some text, a
function or formula, or even a blank.
As you see in the preceding example, a common use of IF is to see how two values
compare and return either one value or the other, depending on how you set up
the test in the rst argument.
IF is often used as a validation check to prevent errors. Suppose that you have a
nancial worksheet that uses a variable percentage in its calculations. The user
must type this percentage each day, but it must never be greater than 10 percent.
To prevent the chance of errors, you could use the IF function to display an error
message in the adjacent cell if you mistakenly type a value outside the permitted
range. Assuming that the percentage is typed in cell A3, here’s the required IF
function:
=IF(A3>.1,"ERROR: the % in A3 IS TOO LARGE","")
Figure14-1 shows how IF can be put to good use in a business application. A c-
titious store shop— Ken’s Guitars (kinda snappy, don’t you think?)— keeps tabs
on inventory in an Excel worksheet.
FIGURE14-1:
Keeping an eye
on inventory at
the guitar shop.
264 PART 4 Dancing with Data
Column D shows the inventory levels, and column E shows the reorder levels. It
works this way: When a product’s inventory level is the same or less than the
reorder level, it is time to order more of the product. (I don’t know about you, but
I love the thought of being surrounded by a bunch of guitars!) The cells in column
F contain a formula.
The formula in cell F8 is =IF(D8<=E8,"ORDER",""). It says that if the number of
Stratoblaster 9000 guitars in stock is the same or less than the reorder level,
return ORDER. If the number in stock is greater than the reorder level, return
nothing. Nothing is returned because three are in stock and the reorder level is
two. In the next row, the number of Flying Xs is equal to the reorder level; there-
fore, cell F9 displays ORDER.
Using IF is easy. Follow these steps:
1. Type two values in a worksheet.
These values should have some meaning to you, such as the inventory levels
example in Figure14-1.
2. Click the cell where you want the result to appear.
3. Type =IF( to start the function.
4. Decide what test you want to perform.
You can see whether the two values are equal; whether one is larger than the
other; whether subtracting one from the other is greater than, equal to, or less
than 0; and so on. For example, to determine whether the rst value equals
the second value, click the rst cell (or type its address), type an equal sign (=),
and then click the second cell (or type its address).
5. Type a comma (,).
6. Type the result that should appear if the test is true.
For example, type “The values are equal”. Text must be enclosed in quotes.
7. Type a comma (,).
8. Type the result that should appear if the test is false.
For example, type “The values are not equal”.
9. Type ) and press Enter.
The IF function can do a whole lot more. Nested IF functions give you a lot more ex-
ibility in performing tests on your worksheet data. A bit of perseverance is necessary
to get through this. Nested means that you can place an IF function inside another IF
function. That is, the inner IF is placed where the true or false argument in the outer
IF goes (or even use internal IFs for both of the arguments). Why would you do this?
CHAPTER 14 Using Lookup, Logical, and Reference Functions 265
The other night, we were deciding where to go for dinner. We were considering
Italian and decided that if we went to an Italian place and it served manicotti, we
would have manicotti. Otherwise, we decided to eat pizza.
Logically, this decision looks like this:
If the restaurant is Italian, then
If the restaurant serves manicotti, then
we will have manicotti
else
we will have pizza
This looks a lot like programming code. I have left out the End If statements on
purpose to prevent confusion because the IF function has no equivalent value.
That’s it! Make note that the inner IF statement has a result for both the true and
false possibilities. The outer IF does not. Here is the structure as nested Excel IF
statements:
=IF(Restaurant=Italian,IF(Restaurant serves manicotti,"manicotti",
"pizza"),"")
If the restaurant were not Italian, it wouldn’t matter what we ate (as indicated by
the third argument of the outer IF being empty).
You can nest up to 64 IF statements, although things are likely to get very com-
plicated once you go beyond 4 or 5.
You can apply a nested IF statement to increase the sophistication of the inventory
worksheet from Figure14-1. Figure14-2 has an additional column: Hot Item. A
Hot Item can take three forms:
»
If the inventory level is half or less of the reorder level and the last sale date is
within the last 30 days, this is a Hot Item. The point of view is that in 30 days or
less the stock sold down to half or less than the reorder level. This means that
the inventory is turning over at a fast pace.
»
If the inventory level is half or less of the reorder level and the last sale date is
within the last 31–60 days, this is a Warm Item. The point of view is that in
31–60 days the stock sold down to half or less than the reorder level. This
means that the inventory is turning over at a medium pace.
»
If neither of the preceding two conditions is met, the item is not assigned any
special status.
266 PART 4 Dancing with Data
There are Hot Items, and there are Warm Items. Both must meet the common cri-
terion that the inventory is 50 percent or less of the reorder level. Only after this
rst condition is met does the second criterion— the number of days since the
last order— come into play. Sounds like a nested IF to me! Here is the formula in
cell G8:
=IF(D8<=(E8*0.5),IF(NOW()-C8<=30,"HOT!",IF(NOW()-
C8<=60,"Warm!","")),"")
Okay, take a breath. I leave no Excel user behind!
The outer IF tests whether the inventory in column D is equal to or less than half
(50 percent) of the reorder level. The piece of the formula that does that is
=IF(D8<=(E8*0.5). This test, of course, produces a true or false answer. If it is
false, the false part of the outer IF is taken (which is just an empty string found at
the end of the formula: ,"")).
That leaves the whole middle part to wade through. Stay with it!
If the rst test is true, the true part of the outer IF is taken. It just so happens that
this true part is another IF function:
IF(NOW()-C8<=30,"HOT!",IF(NOW()-C8<=60,"Warm!",""))
FIGURE14-2:
Looking for hot
inventory items.
CHAPTER 14 Using Lookup, Logical, and Reference Functions 267
The rst argument of the inner IF tests whether the number of days since the last
order date (in column C) is less than or equal to 30. You do this by subtracting the
last order date from today, as obtained from the NOW function.
If the test is true, and the last order date is within the last 30 days, HOT! is returned.
A hot seller indeed! If the test is false...wait, what’s this? Another IF function!
Yes: an IF inside an IF inside an IF.If the number of days since the last order date
is greater than 30, the next nested IF tests whether the number of days is within
the last 60 days:
IF(NOW()-C8<=60
If this test is true, Warm! is returned. If the test is false, nothing is returned.
A few key points about this triple-level IF statement:
»
The IF that tests whether the number of elapsed days is 30 or fewer has a
value to return if true (HOT!) and a value to return for false (whatever is
returned by the next nested IF).
»
The outer IF and the innermost IF return nothing when their test is false.
»
On the surface, the test for 60 or fewer days also would catch a date that is
30days or fewer since the last order date. This is not really what is meant to be.
The test should be whether the number of elapsed days is 60 or fewer but
more than 30. You do not have to actually spell it out this way, because the
formula got to the point of testing for the 60-day threshold only because the
30-day threshold already failed. Gotta watch out for these things!
Choosing the Right Value
The CHOOSE function is ideal for converting a value to a literal. In plain-speak,
this means turning a number, such as 4, into a word, such as April. CHOOSE takes
up to 30 arguments. The rst argument acts as key to the rest of the arguments.
In fact, the other arguments do not get processed per se by the function. Instead,
the function looks at the value of the rst argument and, based on that value,
returns one of its other arguments.
268 PART 4 Dancing with Data
The rst argument must be, or evaluate to, a number. This number in turn indi-
cates which of the following arguments to return. For example, the following
returns Two:
=CHOOSE(2,"One","Two","Three")
The rst argument is 2. This means that the function will return the second argu-
ment in the list of arguments following the rst argument. But watch out— this
is not the same as returning the second argument of the function. It means to
return the second argument, counting from the second argument.
Figure14-3 shows a useful example of CHOOSE.Suppose that you have a column
of months that are in the numerical form (1 through 12). You need to have these
displayed as the month names (January through December). CHOOSE to therescue!
Cells C4:C15 contain formulas with the CHOOSE function. The formula in cell C4
follows:
=CHOOSE(B4,"January","February","March","April","May","June",
"July","August","September","October","November","December")
Cell B4 contains the value 1, so the rst argument starting in the list of possible
returned strings (that is, "January") is returned.
CHOOSE is most often used to return meaningful text that relates to a number,
such as returning the name of a month from its numeric value. But CHOOSE is not
restricted to returning text strings. You can use it to return numbers.
FIGURE14-3:
Choosing what
to see.
CHAPTER 14 Using Lookup, Logical, and Reference Functions 269
Try it yourself! Here’s how:
1. Type a list of numeric values in a worksheet column.
These values should all be small, such as 1, 2, 3, and so on.
2. Click the cell to the right of the rst value.
3. Type =CHOOSE( to start the function.
4. Click the cell to the left (the one that has the rst value) or type its
address.
5. Type a comma (,).
6. Type a list of text strings that each have an association with the numbers
you typed in Step 1.
Each text string should be in double quotes and separated with commas (for
example, "January","February","March").
7. Type ) and press Enter.
The cell to the right of the rst item displays the returned text.
8. Use the ll handle from the rst cell with the formula, and drag the
formula down to all the other cells adjacent to list entries.
Let’s Be Logical
I once worked on a grammar problem that provided a paragraph with no punctua-
tion and asked that the punctuation be added:
That that is is not that that is not is not that it it is
The answer follows:
That that is, is not that that is not. Is not that it? It is.
So true! That that is, such as an apple, is not that that is not, such as an orange.
(Is your head spinning yet?) These logic operators help you work with your data
and also be like Mr. Spock. That’s a logical win-win!
270 PART 4 Dancing with Data
NOT
NOT is a logical operator. It is used to reverse a logical value, turning true to false
or false to true.
Type this formula in a cell:
=5+5=10
The result is the word TRUE.Makes sense. The math checks out. Now try this:
=NOT(5+5=10)
What happens? The word FALSE is returned.
The NOT function provides greater exibility when you’re designing the test por-
tion of a SUMIF function (which you read about in Chapter8). Sometimes, it is
easier to dene what you want omitted from the sum than to dene what you
want included. Figure14-4 shows an example of how this works. The task is to
sum up all orders except those in June. Column A lists the months and column C
lists the amounts.
FIGURE14-4:
Being selective
with summing.
CHAPTER 14 Using Lookup, Logical, and Reference Functions 271
Cell C22 calculates the full sum with this formula:
=SUM(C2:C20)
The total is $3,122.
On the other hand, the formula in cell C24 is
{=SUM(IF(NOT(A2:A20="June"),C2:C20,""))}
This says to sum values in the range C2:C20 only when the associated month in
column A is not June.
Note that this formula is an array formula. When typed, the entry was completed
by pressing Ctrl+Shift+Enter instead of just plain Enter. See Chapter3 for more
information on array formulas.
AND and OR
Next are the AND function and OR function. AND and OR both return a single logi-
cal answer, true or false, based on the values of one or more logical tests (such as
the way IF works):
»
The AND function returns true if all the tests are true. Otherwise, it
returns false.
»
The OR function returns true if any one or more of the tests is true. Otherwise,
it returns false.
The syntax of both AND and OR is to place the tests inside the function’s paren-
theses; the tests themselves are separated by commas. Here is an example that
returns true if the value in cell D10 equals 20 or 30 or 40:
=OR(D10=20,D10=30,D10=40)
Check out how this works. In Figure14-3, earlier in this chapter, you see how you
can use the CHOOSE function to return the name of a month derived from the
number of the month. That works okay, but what if you type a wrong number or
even a non-numerical value as the rst argument in CHOOSE?
As is, the CHOOSE function shown in Figure14-3 returns the #VALUE! error if the
rst argument is a number greater or less than the number of arguments (not
counting the rst argument). So as is, the function only works when the rst
argument evaluates to a number between 1 and 12. If only life were that perfect!
272 PART 4 Dancing with Data
The next-best thing, then, is to include a little validation in the function. Think
this through. Both statements must be true:
»
The rst argument must be greater than 0.
»
The rst argument must be less than 13.
The formula that uses CHOOSE needs an overhaul, and here it is, courtesy of the
AND function:
=IF(AND(B4>0,B4<13),CHOOSE(B4,"January","February","March",
"April","May","June","July","August","September","October",
"November","December"),"That is not a month!")
Wow, that’s a mouthful (or a cell-full). The CHOOSE function is still there, but it
is nested inside an IF.The IF has a test (which I explain shortly). If the test returns
true, the CHOOSE function returns the name of the month. If the IF test returns
false, a simple That is not a month! message is returned. Figure14-5 shows
this in action.
The test part of the IF function is this:
AND(B4>0,B4<13)
The AND returns true if the value in Cell B4 is both greater than 0 and less than 13.
When that happens, the true part of the IF statement is taken, which uses the
CHOOSE statement to return a month name. Otherwise, the "That is not a
month!" statement is displayed. In Figure14-5, this is just what happens in cells
C9 and C15, which look at the data values in cells B9 and B15, respectively.
FIGURE14-5:
Being logical
about what to
choose.
CHAPTER 14 Using Lookup, Logical, and Reference Functions 273
Can you gure out how to accomplish the same thing by using OR instead of AND?
Think for a moment and then look at the answer:
=IF(OR(B4<1,B4>12),"That is not a month!",CHOOSE(B4,"January",
"February","March","April","May","June","July","August",
"September","October","November","December"))
AND returns true when every condition is true. OR returns true when any condi-
tion is true.
Here’s how to use AND or OR:
1. Click a cell where you want the result to appear.
2. Type either =AND( or =OR( to start the function.
3. Type one or more logical tests. (In practical use, you would have at least
two.)
A test typically is a comparison of values in two cells or an equation, such as
A1=B1 or A1+B1=C1. Separate the tests with commas.
4. Type ), and press Enter.
If you type the AND function, the result is true if all the tests are true. If you
type the OR function, the result is true if at least one of the tests is true.
XOR
OR (see earlier in the chapter) returns TRUE when at least one condition is true.
This makes sense, considering that it’s the word or— as in “this or that.” So what
does XOR mean? XOR is an acronym for Exclusive Or. XOR returns TRUE or FALSE
depending on the number of conditions. This can be confusing! (Please don’t
shoot me; I’m just the messenger!)
Seriously, you really must wonder what is going on here. I have always found that
the best way to think of XOR is that it is a variation of OR.Only one condition
needs to be true in an OR test to have it return TRUE.With XOR, each condition’s
logical value and the number of conditions both determine if XOR returns TRUE or
FALSE.Believe it or not, there are useful applications for this.
Figure14-6 shows a worksheet that compares the percentage of change in reve-
nue month to month over a 3-year span. For example, Feb 2011 had an increase of
9 percent from the same period in the previous year. Feb 2012 has an increase of
11 percent from the same period in 2011, and Feb 2013 had an increase of 16 percent
274 PART 4 Dancing with Data
from Feb 2012. In a nutshell, revenue has been increasing each February compared
with the previous February. This is the type of news that makes business manager
types all tingly and ready to go out dancing.
The revenue percentage change is shown for all 12 months over the 3-year span.
The XOR is put in column G and is used with the two conditions in the same row.
In other words, cell G5 contains an XOR that has two conditions— a test to see
whether the percentage change from Feb 2011 to Feb 2012 is an increase and a test
to see whether the percentage change of Feb 2012 to Feb 2013 is also an increase.
The revenue percentage change has been increasing— good news— and the XOR
returns the word FALSE.When a manager looks over this report, they can scan
column G, and if they see the word FALSE, that’s a signal to ignore. The question
is, did revenue dip somewhere along the 3 years, in February? The answer is no—
that is, the answer is FALSE.The manager skips looking any further at that line.
The formula in cell G5 looks like this:
=XOR(D5>B5,F5>D5)
To the manager’s eye, other lines in the worksheet are worthy of attention. For
example, cell G15 contains an XOR that looks at the revenue change for December
over the 3-year period. Sure enough, the revenue percentage change went up and
then down— not good news. The XOR function returns TRUE.
FIGURE14-6:
Using XOR to nd
where data is not
what was
expected.
CHAPTER 14 Using Lookup, Logical, and Reference Functions 275
Finding Where the Data Is
You can nd a plethora of things with the ADDRESS, ROW, ROWS, COLUMN,
COLUMNS, and OFFSET functions.
ADDRESS
The ADDRESS function takes a row number and a column number as arguments
and returns a standard cell reference (cell address). For example, if you pass the
row number 4 and the column number 3, the function returns C4. ADDRESS can
return an absolute or relative reference in either of Excel’s two reference formats.
Before I get to the details, I review the dierences between absolute and relative
cell references:
»
A relative reference is expressed as just the column letter and row number (for
example, M290). When you copy a formula that contains a relative cell
reference, the reference— the row number and the column letter— is
adjusted to reect the location to which you copied the formula.
»
An absolute reference has a dollar sign in front of the column letter and the
row number (for example, $M$290). When you copy a formula that contains
an absolute cell reference, the reference does not change.
»
A mixed reference has a dollar sign in front of the column letter or the row
number (for example, $M290 or M$290). When you copy a formula that
contains a mixed cell reference, the part of the reference with the dollar sign
does not change but the other part does.
Figure14-7 shows a worksheet in which typing a formula with a relative cell ref-
erence causes a problem. Totals are the result of adding the tax to the amount. The
tax is a percentage (0.075) for a 7.5 percent tax rate. This percentage is in cell C1
and is referenced by the formulas. The rst formula that was typed is in cell C7
and looks like this: =B7*(1+C1).
The formula in cell C7 works correctly. It references cell C1 to calculate the total.
But if you use the ll handle to copy the formula from cell C7 to cells C8 and C9,
there’s a problem. The reference to cell C1 changed to cell C2 and C3. Because these
cells are empty, the results in cells C8 and C9 are incorrect; they are the same as
the amounts to the left. (No tax is added.)
To better understand, column D displays the formulas that are in column C.When
the formula in cell C7 was dragged down, the C1 reference changed to C2in cell C8,
and to C3in cell C9. Often, this is what you want— for Excel to automatically
276 PART 4 Dancing with Data
change cell references when a formula is copied. But sometimes, as in this situa-
tion, it is not what you want. You need an absolute cell reference.
The formula in cell C17 is almost identical to the one in cell C7 except that the
reference to cell C1 has been made row absolute by placing a dollar sign in front of
the row number. The formula in cell C17 looks like this: =B17*(1+C$1). When this
formula was dragged down into C18 and C19, the reference was not adjusted but
stayed pointing at cell C1. Note that in this example, only the row part of the refer-
ence is made absolute. That’s all that is necessary. You could have made the refer-
ence completely absolute by doing this: =B17*(1+$C$1). The result would be the
same, but it’s not required in this example.
Put a dollar sign in front of the column letter of a cell reference to create an abso-
lute column reference. Put a dollar sign in front of the row number to create an
absolute row reference.
Excel supports two cell reference styles: the good old A1 style and the R1C1 style.
You see the A1 style— a column letter followed by a row number— throughout
this book (D4 or B2:B10, for example). The R1C1 style uses a numerical system for
both the row and the column, such as this: R4C10. In this example, R4C10 means
row 4 column 10.
To change the cell reference style, choose File ➪ Options and check the R1C1 refer-
ence style in the Working with Formulas area on the Formulas tab. Using the R1C1
format also forces the columns on the worksheet to display as numbers instead of
the lettering system. This is useful when you’re working with a large number of
FIGURE14-7:
Changing a
reference from
relative to
absolute.
CHAPTER 14 Using Lookup, Logical, and Reference Functions 277
columns. For example, column CV positionally is the 100th column. Remembering
100 is easier than remembering CV.
To get back to the ADDRESS function, it takes up to ve arguments:
»
The row number of the reference
»
The column number of the reference
»
A number that tells the function how to return the reference. The default is 1,
but it can be
•
1 for full absolute
•
2 for absolute row and relative column
•
3 for relative row and absolute column
•
4 for full relative
»
A value of 0 or 1 to tell the function which reference style to use:
•
0 uses the R1C1 style.
•
1 (the default if omitted) uses the A1 style.
»
A worksheet reference or an external workbook and worksheet reference
Only the rst two arguments are required: the row number and column number
being addressed. The function returns the specied reference as text. Table14-2
shows some examples of using the ADDRESS function.
Use ADDRESS this way:
1. Click a cell where you want the result to appear.
2. Type =ADDRESS( to start the function.
3. Type a row number, a comma (,), and a column number.
You can also type references to cells where those values are located.
4. If you want the result to be returned in a mixed or full reference, type a
comma (,) and the appropriate number: 2, 3, or 4.
5. If you want the result to be returned in R1C1 style, type a comma (,) and
type 0.
6. If you want the result to be a reference to another worksheet, type a
comma and put the name of the worksheet in double quote marks.
278 PART 4 Dancing with Data
If you want the result to be a reference to an external workbook, type a comma
(,) and type the workbook name and worksheet name together. The workbook
name goes in brackets, and the entire reference goes in double quote marks,
such as this: "[Book1]Sheet2".
7. Type ) and press Enter.
Instead of typing a row number and column number directly in ADDRESS, you can
type cell references. However, the values you nd in those cells must evaluate to
numbers that can be used as a row number and column number.
TABLE14-2 Using the ADDRESS Function
Syntax Result Comment
=ADDRESS(5,2) $B$5 Only the row and column are provided as arguments.
The function returns a full absolute address.
=ADDRESS(5,2,1) $B$5 When a 1 is used for the third argument, a full
absolute address is returned. This is the same as
leaving out the third argument.
=ADDRESS(5,2,2) B$5 When a 2 is used for the third argument, a mixed
reference is returned, with the column relative and
therow absolute.
=ADDRESS(5,2,3) $B5 When a 3 is used for the third argument, a mixed
reference is returned, with the column absolute and
the row relative.
=ADDRESS(5,2,4) B5 When a 4 is used for the third argument, a full relative
reference is returned.
=ADDRESS(5,2,1,0) R5C2 When the fourth argument is zero, an R1C1-style
reference is returned.
=ADDRESS(5,2,3,0) R[5]C2 This example tells the function to return a mixed
reference in the R1C1 style.
=ADDRESS(5,2,1,1,"Sheet4") Sheet4!$B$5 The fth argument returns a reference to a worksheet
or external workbook. In this example, an A1-style
reference to cell B5 on Sheet 4 is returned.
=ADDRESS(5,2,1,0,"Sheet4") Sheet4!R5C2 This example returns an R1C1-style reference to B5 on
Sheet 4.
CHAPTER 14 Using Lookup, Logical, and Reference Functions 279
INDIRECT
The ADDRESS function returns the location of a cell. What if you need to know
what’s inside the cell referenced by ADDRESS? Well, let me be direct by telling you
about the INDIRECT function.
INDIRECT returns the value of a cell. The function argument needs to be text. In
other words use "D5" instead of just D5 to have the function return the value in cell
D5. INDIRECT is quite useful when used with ADDRESS.If, for example, ADDRESS
provides a cell reference of D8, then INDIRECT tells us what’s actually in that cell.
These functions go hand in hand because ADDRESS does, indeed, return a
textvalue.
The formula looks like this:
=INDIRECT("D8")
Or like this:
=INDIRECT(ADDRESS(8,4))
Use INDIRECT like this:
1. Click a cell where you want the result to appear.
2. Type =INDIRECT( to start the function.
3. Type a cell address in double quote marks, or use the ADDRESS function
to return the cell address.
4. Type ) and press Enter.
ROW, ROWS, COLUMN, and COLUMNS
The ADDRESS function is rarely used on its own. Most often, it is used as part of a
more complex formula. A useful example of ADDRESS follows the discussion of
ROW, ROWS, COLUMN, and COLUMNS.
ROW and COLUMN are passed a reference to a cell or range and return the row
number or the column number, respectively. Sounds simple enough. These func-
tions take a single optional argument. The argument is a reference to a cell or
range. The function returns the associated row number or column number. When
the reference is a range, it is the rst cell of the range (the upper left) that is used
by the function.
280 PART 4 Dancing with Data
ROW and COLUMN are particularly useful when the argument is a name (for a
named area). When you use ROW or COLUMN without an argument, it returns the
row number or column number of the cell the function is in. Table14-3 shows
examples of ROW and COLUMN.
The ROWS and COLUMNS functions (notice that these are now plural), respec-
tively, return the number of rows or the number of columns in a reference (see
Table14-4).
Now you are getting somewhere. You can use these functions with ADDRESS to do
something useful. Here’s the scenario: You have a named range in which the bot-
tom row has summary information, such as averages. You need to get at the bot-
tom row but don’t know the actual row number. Figure14-8 shows this situation.
The Team_Scores range is B3:C9. Row 9 contains the average score. You need that
value in a calculation, even if another team is added to the list and the row
numberchanges.
TABLE14-4 Using ROWS and COLUMNS
Formula Result
=ROWS(Team_Scores) Number of rows in the Team_Scores range
=COLUMNS(Team_Scores) Number of columns in the Team_Scores range
TABLE14-3 Using ROW and COLUMN
Formula Result
=ROW(D3) 3
=ROW(D3:G15) 3
=COLUMN(D3) 4
=COLUMN(D3:G15) 4
=ROW(Team_Scores) The rst row of the Team_Scores range
=COLUMN(Team_Scores) The rst column of the Team_Scores range
CHAPTER 14 Using Lookup, Logical, and Reference Functions 281
Cell B12 uses a combination of ADDRESS, ROW, ROWS, and COLUMN to determine
the cell address where the average score is calculated. That formula follows:
=ADDRESS(ROW(Team_Scores)+ROWS(Team_Scores)-1,COLUMN(Team_
Scores)+1)
»
ROW returns the row number of the rst cell of Team_Scores. That row
number is 3.
»
ROWS returns the number of rows in the named range. That count is 7.
Adding these two numbers is not quite right. A 1 is subtracted from that total to
give the last row (9). In this example, you need only COLUMN to get the column
number because it understood that the range’s second column is the column of
scores. In other words, you have no idea how many rows the range has, so ROW
and ROWS are both used, but you do know the scores are in the range’s second
column. This tells you that cell C9 contains the average score. Now what?
Cell B16 contains an IF that uses the address to perform its calculation:
=IF(@INDIRECT(ADDRESS(@ROW(Team_Scores)+ROWS(Team_Scores)-1,
@COLUMN(Team_Scores)+1))>100,"Great Teamwork!",
"Try again")
The IF function tests whether the average score is greater than 100. If it is, the
Great Teamwork! message is displayed. This test is possible because the ADDRESS,
ROW, ROWS, and COLUMN functions all help give the IF function the address of
the cell where the average score is calculated. The INDIRECT function returns the
actual value.
FIGURE14-8:
Using reference
functions to nd
a value.
282 PART 4 Dancing with Data
Using ROW, ROWS, COLUMN, or COLUMNS is easy. Here’s how:
1. Click the cell where you want the results to appear.
2. Type =ROW(, =ROWS(, =COLUMN(, or =COLUMNS( to start the function.
3. Type a reference or drag the mouse over an area of the worksheet.
4. Type ) and press Enter.
Again, these functions are rarely used alone; they are almost always used in a
more complex formula, as in the preceding example.
OFFSET
The OFFSET function lets you get the value of a cell or range that is oset from a
specied cell or range by a certain number of rows and/or columns. For example,
cell E4 is oset from cell B4 by three columns because it is three columns to the
right. OFFSET takes up to ve arguments. The rst three are required:
»
A cell address or a range address: Named ranges are not allowed.
»
The number of rows to oset: This can be a positive or negative number.
Use 0 for no row oset.
»
The number of columns to oset: This can be a positive or negative
number. Use 0 for no column oset.
»
The number of rows in the returned range: The default is the number of
rows in the reference range (the rst argument).
»
The number of columns to return: The default is the number of columns in
the reference range.
If you omit the last two arguments, OFFSET returns a reference to a single cell. If
you include a value greater than 1 for either or both, the function’s return refer-
ences a range of the specied size with the top-left cell at the specied oset.
Figure14-9 shows some examples of using OFFSET.Columns A through C contain
a ranking of the states in the United States by size in square miles. Column E
shows how OFFSET has returned dierent values from cells that are oset from
cell A3.
CHAPTER 14 Using Lookup, Logical, and Reference Functions 283
Some highlights follow:
»
Cell E4 returns the value of cell A3 because both the row and column oset is
set to 0: =OFFSET(A3,0,0).
»
Cell E7 returns the value you nd in cell A1 (the value also is A1). This is
because the row oset is –2. From the perspective of A3, minus two rows is
row number 1: =OFFSET(A3,-2,0).
»
Cell E8 displays an error because OFFSET is attempting to reference a column
that is less than the rst column: =OFFSET(A3,0,-2).
»
Cell E10 makes use of the two optional OFFSET arguments to tell the SUM
function to calculate the sum of the range C4:C53:
=SUM(OFFSET(A3,1,2,50,1)).
Here’s how to use the OFFSET function:
1. Click a cell where you want the result to appear.
2. Type =OFFSET( to start the function.
3. Type a cell address or click a cell to get its address.
4. Type a comma (,).
5. Type the number of rows you want to oset where the function looks for
a value.
This number can be a positive number, a negative number, or 0 for no oset.
6. Type a comma (,).
FIGURE14-9:
Finding values by
using the OFFSET
function.
284 PART 4 Dancing with Data
7. Type the number of columns you want to oset where the function looks
for a value.
This can be a positive number, a negative number, or 0 for no oset.
8. Type ) and press Enter.
OFFSET is another of those functions that can be used alone but is usually used as
part of a more complex formula.
Looking It Up
Excel has a neat group of functions that let you extract data from lists and tables.
What is a table? A table is a dedicated matrix of rows and columns that collectively
form a cohesive group of data. Tables usually have labels in the top row or the left
column that identify the columns and rows of data. The remainder of the table
contains the data itself.
HLOOKUP and VLOOKUP
The HLOOKUP and VLOOKUP functions extract the data from a particular cell in a
table. HLOOKUP starts by searching across the rst row of the table to nd a value
that you specify. When it nds that value, it goes down the column a specied
number of rows and returns the value in the target cell. VLOOKUP works the same
way except that it searches down the rst column of the table and then moves
across a specied number of columns. By the way, H and V stand for horizontal
and vertical.
HLOOKUP takes four arguments, and the rst three are required:
»
The value to nd in the top row of the table: This can be text or a number.
»
The address of the table itself: This is either a range address or a named
range.
»
The row oset from the top row: This is not a xed row number but rather
the number of rows relative from the top row.
»
A true or false value: If true (or omitted), a partial match is acceptable for
Step 1 (see steps below). If false, only an exact match is allowed.
CHAPTER 14 Using Lookup, Logical, and Reference Functions 285
Figure14-10 shows how HLOOKUP pulls values from a table and displays them
elsewhere in the worksheet. This function is quite useful if you need to print a
report with a dedicated print area and must include some, but not all, of the data
in the table. This example uses the HLOOKUP function to extract the desired data
and display it for printing.
Why not just use a cell reference to the table cell that contains the desired data? A
cell reference will not return the correct data if the table is moved or if one or more
columns are added. With HLOOKUP and VLOOKUP, you know you’ll always get
data from the correct column or row.
In Figure14-10, the table is the range B20:H21, which has been assigned the name
Daily_Results. Each cell in the range C6:C12 uses HLOOKUP to locate a specic
value in the table. For example, cell C6 has this formula:
HLOOKUP("Monday",Daily_Results,2,FALSE)
»
The rst argument: Tells the function to search for Monday in the rst row of
the table.
»
The second argument: Species the table itself by its assigned name.
»
The third argument: Tells the function to return the data in the second row
of the specied column. This table has just two rows, but there is no eective
size limit to the table that you use with HLOOKUP.
FIGURE14-10:
Using HLOOKUP
to locate data
in a table.
286 PART 4 Dancing with Data
»
The fourth argument: Species that an exact match for Monday must be
found. If you set this argument to true or omit it, HLOOKUP nds an approxi-
mate match. For approximate matching to work properly, the values in the
row must be sorted, left to right, in ascending order.
VLOOKUP works in the same way, except that it nds a value in the rst column
of the table and then moves over a specied number of columns. The arguments
follow:
»
The value to nd in the leftmost column of the table.
»
The address of the table itself: This is either a range or a named area.
»
The column oset from the leftmost column: This is not a xed column
number but rather the number of columns relative from the leftmost column.
»
A true or false value: If true (or omitted), VLOOKUP nds an approximate
match. If false, an exact match is required. For an approximate match, the
column must be sorted in ascending order.
Figure14-11 shows an example of using VLOOKUP.The worksheet displays prod-
ucts and annual revenue data for the ctitious guitar shop. The range A6:D27 has
been named Sales.
FIGURE14-11:
Using VLOOKUP
to locate data
in a table.
CHAPTER 14 Using Lookup, Logical, and Reference Functions 287
The goal is to use VLOOKUP to extract the sales amount for the Wireless Gig Kit.
However, the product names are in the second column of the Sales range, and
VLOOKUP normally searches in the rst column. You can use OFFSET to force
VLOOKUP to search for Wireless Gig Kit in the second column of the range. This is
the formula in cell B3:
=VLOOKUP("Wireless Gig Kit",OFFSET(Sales,0,1),3,FALSE)
Note that the oset specied as the third argument to VLOOKUP is 3. That’s
because the sales gures are in the third column relative to the Product column,
where VLOOKUP is performing its search.
Here’s how to use either HLOOKUP or VLOOKUP:
1. Click a cell where you want the result to appear.
2. Type either =HLOOKUP( or =VLOOKUP( to start the function.
3. If using
•
HLOOKUP: Type the value that you want to nd in the top row of the table.
•
VLOOKUP: Type the value that you want to nd in the rst column of the
table.
4. Type a comma (,).
5. Type the range address that denes the table of data, or type its name, if
it has been assigned one.
6. Type a comma (,).
7. If using
•
HLOOKUP: Type a number to indicate the row of the value to return.
•
VLOOKUP: Type a number to indicate the column of the value to return.
The number you type here is relative to the range or area dened in the
second argument.
8. (Optional) Type a comma (,) and then type FALSE.
This forces the function to nd an exact match for the value typed in the rst
argument.
9. Type ) and press Enter.
Excel also provides the LOOKUP function, which is specialized for returning values
from single-column or single-row ranges. See Excel Help for more information
on this function.
288 PART 4 Dancing with Data
XLOOKUP
XLOOKUP takes the power of VLOOKUP and HLOOKUP up a notch. A limitation of
VLOOKUP and HLOOKUP is that they can only return a single value. Sometimes
you need more of an answer from a table lookup.
XLOOKUP can return any number of columns or rows. Wow! This is really handy!
Figure 14-12 shows a table of employee data. Column A has the names of the
employees. Using XLOOKUP we can get the rest of the employee information.
Cell A14 has the name of an employee. Cell B14 contains the XLOOKUP function:
=XLOOKUP(A14,A1:A7,B1:E7)
XLOOKUP takes the name in cell A14, and looks for it in the rst column of the
table. If there is a match, then the information for the next four columns is
returned. Since the return range is specied to be four columns (B1:E7), then four
columns from the employee’s row are returned. Cell B14 contains the formula.
XLOOKUP takes six arguments, and the rst three are required:
»
The value to nd in the table: This can be text or a number.
»
The address where the search criteria can be found: This is either a range
address or a named range.
»
The range from which the data is returned: This can be single or multiple
rows or columns:
»
An optional message to display if the value is not found.
FIGURE14-12:
Getting multiple
columns of data
with XLOOKUP.
CHAPTER 14 Using Lookup, Logical, and Reference Functions 289
»
The match mode: The default is exact match. Optionally this can be set to an
approximate match.
»
The search mode: An optional setting whether to search from the rst part of
the range or the last part. The default is from the rst.
Here’s how to use the XLOOKUP function.
1. Click a cell where you want the result to appear.
2. Type =XLOOKUP( to start the function.
3. Click a cell that has the search criteria, or type it directly into the
function using double quotes.
4. Type a comma (,).
5. Select a range in the table where to search for the criteria.
6. Type a comma (,).
7. Select the range in the table that has the data to return.
This can be multiple rows or columns.
8. Type ) and press Enter.
XLOOKUP is an enhancement of both HLOOKUP and VLOOKUP.
MATCH and INDEX
The MATCH function returns the relative row number or column number of a
value in a table. The key point here is that MATCH returns the relative location but
does not return the value itself.
This function is useful when you need an item’s position. You are not often
interested in this information by itself but may use it in a more complex formula.
I show you how shortly.
MATCH takes three arguments:
»
The value to search for: This can be a number, text, or a logical value.
»
Where to look: This is a range spanning a single row or column, or a named
area that comprises a single row or column.
»
How the match is to be applied: This argument is optional.
290 PART 4 Dancing with Data
The third argument can be one of three values. They work as follows:
»
1 tells MATCH to nd the largest value that is less than or equal to the lookup
value. The range must be sorted in ascending order. This is the default value if
the argument is omitted.
»
–1 tells MATCH to nd the smallest value that is greater than or equal to the
lookup value. The range must be sorted in descending order.
»
0 tells MATCH to nd the rst value that is an exact match. The range need
not be sorted.
Figure14-13 shows the products and revenue for the guitar shop. Note that the
information has been sorted in ascending order according to the Amount column.
The goal is to get a count of how many products have sales less than $10,000.
MATCH makes this easy, as shown in Figure14-13. This formula is in cell B4:
=MATCH(10000,OFFSET(Sales,0,3,ROWS(Sales),1))-1
Take this formula apart from the inside out. First, you know that MATCH needs a
reference to the column where it is to search— in this case, the Amount column
in the Sales range. Sounds like a job for OFFSET! Type the following:
OFFSET(Sales,0,3,ROWS(Sales),1)
FIGURE14-13:
Making a match.
CHAPTER 14 Using Lookup, Logical, and Reference Functions 291
This returns a range that has the following characteristics:
»
Oset by no rows and three columns from the Sales range
»
Has a height equal to the number of rows in Sales
»
Has a width of one column
Now that you have this range, you can tell MATCH to look for the largest value
that is less than or equal to 10,000. Because the data is sorted, the relative position
of this value in the range is one more than the number of products with sales less
than $10,000. Why one more? The heading row at the top of the range is counted,
too— so you subtract 1 to get the nal answer.
Here’s how to use the MATCH function:
1. Click a cell where you want the result to appear.
2. Type =MATCH( to start the function.
3. Type a value to match.
This can be a numeric, text, or logic value. You can type a cell address provided
that the referenced cell has a usable value.
4. Type a comma (,).
5. Type the range in which to look for a match.
This can be a range reference or a named area.
6. (Optional) Type a comma (,) and type –1, 0, or 1 to tell the function how to
make a match.
The default is 1. A 0 forces an exact match.
7. Type ) and press Enter.
The information returned by MATCH can be helpful when you use it with the
INDEX function. INDEX returns the value found at a specied row-and-column
intersection within a table. You can use MATCH to nd the row and nd the col-
umn and then use INDEX to get the actual data.
INDEX takes three arguments:
»
The table to look in as a range address or range name
»
The row number relative to the table’s rst row
»
The column number relative to the table’s leftmost column
292 PART 4 Dancing with Data
The return value is the value of the cell where the row and column intersect.
Figure14-14 shows an example in which INDEX retrieves a value from a table that
summarizes some guitar-shop sales by product and quarter. The table range in
this example has been named Sales_by_qtr.
The following formula, in cell C2, extracts the sales for 6 Foot Cables for Qtr 2:
=INDEX(Sales_by_qtr,MATCH("6 Foot Cables",OFFSET(Sales_by_
qtr,0,0,ROWS(Sales_by_qtr),1),0),MATCH("Qtr 2",
OFFSET(Sales_by_qtr,0,0,1,COLUMNS(Sales_by_qtr))))
Wow, that’s quite a cell-full of formula! But you already know everything you
need to understand it. The rst argument of INDEX is no mystery; it is simply the
name assigned to the table. The second and third arguments, which tell INDEX
what cell to look in, are complicated. Look at the rst one, for the row argument:
MATCH("6 Foot
Cables",OFFSET(Sales_by_qtr,0,0,ROWS(Sales_by_qtr),1),0)
You want to look down the table’s rst column, where the product names are
listed, and nd the row that contains 6 Foot Cables. You also know that the MATCH
function is just right for this job and that the function needs to know where to
look. In other words, you must tell it the address of the table’s rst column. Here
is where OFFSET comes into play:
OFFSET(Sales_by_qtr,0,0,ROWS(Sales_by_qtr),1)
FIGURE14-14:
Using INDEX
to extract data
from a table.
CHAPTER 14 Using Lookup, Logical, and Reference Functions 293
This call to OFFSET returns a range address that has the following
characteristics:
»
Is located with reference to the range Sales_by_qtr
»
Is oset from Sales_by_qtr by zero rows and zero columns (in other words,
starts at cell B7)
»
Contains the same number of rows as Sales_by_qtr
»
Contains one column
The result is that this call to OFFSET returns the range B7:B18. The MATCH func-
tion becomes this, in eect:
MATCH("6 Foot Cables",B7:B18,0)
Because an exact match is requested, the data does not have to be sorted. MATCH
nds the search text in the fourth row relative to the top of the table. This is the
value that INDEX uses for its row argument. The column argument to INDEX is
handled in the same way.
Here’s how to use the INDEX function:
1. Click a cell where you want the result to appear.
2. Type =INDEX( to start the function.
3. Type a reference to the table.
You can drag the mouse over the range or type its address. If the table has
been named, you can type the name.
4. Type a comma (,).
5. Type the row number relative to the table’s rst row.
This number can be the result of a calculation or the value returned from a
function.
6. Type a comma (,).
7. Type the column number relative to the table’s leftmost column.
This number can be the result of a calculation or the value returned from a
function.
8. Type ) and press Enter.
294 PART 4 Dancing with Data
FORMULATEXT
FORMULATEXT displays the syntax of a formula. It’s simple and yet serves a great
feature. Think about it. You might have a workbook full of formulas; however, all
you see is the result of the calculations. What if you need to see the formulas
themselves? It’s great to have the answer given by a calculation, but often, you
need to know how the calculation works!
FORMULATEXT to the rescue! This function references a cell that has a formula
and displays the formula without having it calculate the answer. Figure 14-15
shows how this works. Columns A and B contain numbers. Column C contains
formulas that return calculated values using the numbers in columns A and B.
Column D uses FORMULATEXT to display the formulas in column C.
Here’s how to use the FORMULATEXT function:
1. Click a cell where you want the result to appear.
2. Type =FORMULATEXT( to start the function.
3. Click a cell that has a formula.
4. Type ) and press Enter.
There is a setting in Excel’s options to always display formulas as syntax instead
of showing the calculated results. Look in the Display options for this worksheet
on the Advanced tab in Excel Options to see where this option is set. This setting
converts all formulas to text, and you can see them all. The caveat in using this
approach is that no calculations occur! If you need to see all the calculations’ inner
workings, this is a good option. However, if you want to still have the formulas
calculate answers and want to see how they are written, use FORMULATEXT.
FIGURE14-15:
Using
FORMULATEXT to
see the syntax of
formulas.
CHAPTER 14 Using Lookup, Logical, and Reference Functions 295
NUMBERVALUE
NUMBERVALUE is used to format numbers that appear as text back to appearing
as actual numbers. For example, your worksheet might display a value such as
14.25%. Excel will treat this correctly as a number if used in a formula, function,
or calculation, but the percent sign is not part of the number.
A percentage is usually a decimal-based number.
The 14.25 percent, when not formatted, is .1425.
Perhaps you need to display such a nice-looking number for the raw value it really
is. This is where NUMBERVALUE comes to the rescue.
Figure14-16 shows a worksheet with two numbers in column A that, in one way
or another, appear to be a bit non-numeric. Besides 14.25 percent, there is “1 2 3
4” (spaces between each digit).
Column B shows how the numbers look when you use NUMBERVALUE.For exam-
ple, cell B3 contains this:
=NUMBERVALUE(A3)
FIGURE14-16:
Using
NUMBERVALUE
to return the
numeric
presentation
of a number.
CHAPTER 15 Digging Up the Facts 297
Chapter15
Digging Up the Facts
In this chapter, I show you how to use Excel’s information functions, which you
use to obtain information about cells, ranges, and the workbook you’re working
in. You can even get information about the computer you’re using. What will
they think of next?
The information functions are great for getting formulas to focus on just the data
that matter. Some functions even help shield you from Excel’s confusing error
messages. The rst time I saw the #NAME? error, I thought Excel was asking me
to enter a name (just another of the more exciting Excel moments). Now at least I
know to use the ISERROR or ERROR.TYPE functions to make error messages more
meaningful. And after reading this chapter, so will you!
Getting Informed with the CELL Function
The CELL function provides feedback about cells and ranges in a worksheet. You
can nd out what row and column a cell is in, what type of formatting it has,
whether it’s protected, and so on.
IN THIS CHAPTER
»
Getting information about a cell or
range
»
Finding out about Excel or your
computer system
»
Testing for numbers, text, and errors
298 PART 4 Dancing with Data
CELL takes two arguments:
»
The rst argument, which is enclosed in double quotes, tells the function what
kind of information to return.
»
The second argument tells the function which cell or range to evaluate. If you
specify a range that contains more than one cell, the function returns
information about the top-left cell in the range. The second argument is
optional; when it isn’t provided, Excel reports back on the most recently
changed cell.
Table15-1 shows the list of possible entries for the rst argument of the CELL
function.
The second argument, whether it’s there or not, plays a key role in how the CELL
function works. When it’s included, the second argument is a cell address, such as
B12, or a range name, such as Sales. Of course, you could have a range that is only
one cell, but I won’t confuse the issue!
If you type a nonexistent range name for the second argument, Excel returns the
#NAME? error. Excel can’t return information about something that doesn’t exist!
An interesting way to use CELL is to keep track of the last entry on a worksheet.
Say you’re updating a list of values. The phone rings, and you’re tied up for a
while on the call. When you get back to your list, you’ve forgotten where you left
o. Yikes! What a time to think “If only I had used the CELL function!”
Figure15-1 shows such a worksheet. Cell B18 displays the address of the last cell
that was changed.
Using CELL with the lename argument is great for displaying the workbook’s
path. This technique is common for printed worksheet reports. Being able to nd
the workbook le that a report was printed from 6 months ago is a real time-
saver. Don’t you just love it when the boss gives you an hour to create a report,
doesn’t look at it for 6 months, and then wants to make a change? Here’s how you
type the CELL function to return the lename:
=CELL("filename")
You can format cells in many ways. When the rst argument of CELL is format, a
code is returned that corresponds to the formatting. The possible formats are
those listed in the Format Cells dialog box. Table15-2 shows the formats and the
code that CELL returns.
CHAPTER 15 Digging Up the Facts 299
TABLE15-1 Selecting the First Argument for the CELL Function
Argument Example Comment
address =CELL("address") Returns the address of the last changed cell.
col =CELL("col",Sales) Returns the column number of the rst cell in the Sales
range.
color =CELL("color",B3) Tells whether a particular cell (in this case, cell B3) is format-
ted in such a way that negative numbers are represented in
color. The number, currency, and custom formats have
selections for displaying negative numbers in red. If the cell
is formatted for color-negative numbers, a 1 is returned;
otherwise, a 0 is returned.
contents =CELL("contents",B3) Returns the contents of a particular cell (in this case, cell B3).
If the cell contains a formula, returns the result of the for-
mula and not the formula itself.
filename =CELL("filename") Returns the path, lename, and worksheet name of the
workbook and worksheet that has the CELL function in it (for
example, C:\Customers\[Acme Company]Sheet1). The
function results in a blank answer in a new workbook that
has not yet been saved.
format =CELL("format",D12) Returns a cell’s number format (in this case, cell D12). See
Table15-2 for a list of possible returned values.
parentheses =CELL("parentheses",
D12)
Returns 1 if a cell (in this case, D12) is formatted to have
either positive values or all values displayed with parenthe-
ses. Otherwise, 0 is returned. A custom format is needed to
make parentheses appear with positive values in the rst
place.
prefix =CELL("prefix",R25) Returns the type of text alignment in a cell (in this case, cell
R25). There are a few possibilities: a single quotation mark (’)
if the cell is left-aligned; a double quotation mark (") if the cell
is right-aligned; a caret (^) if the cell is set to centered; or a
backslash (\) if the cell is ll-aligned. If the cell being evalu-
ated is blank or has a number, the function returns nothing.
protect =CELL("protect",D12) Returns 1 if a cell’s protection (in this case, cell D12) is set to
locked; otherwise, a 0 is returned. The returned value is not
aected by whether the worksheet is currently protected.
row =CELL("row",Sales) Returns the row number of the rst cell in the Sales range.
type =CELL("type",D12) Returns a value corresponding to the type of information in
acell (in this case, cell D12). There are three possible values:
b if the cell is blank; l if the cell has alphanumeric data; and
vfor all other possible values, including numbers and errors.
width =CELL("width") Returns the width of the last changed cell, rounded to an
integer. For example, a width of 18.3 is returned as 18.
300 PART 4 Dancing with Data
Using CELL with the format argument lets you add a bit of smarts to your work-
sheet. Figure15-2 shows an example of CELL making sure information is correctly
understood. The dates in column A are of the d-mmm format. The downside of
this format is that the year is not known. So cell A1 has been given a formula that
uses CELL to test the dates’ format. If the d-mmm format is found in the rst date
(in cell A4), cell A1 displays a message that includes the year from cell A4. After
all, cell A4 has a year; it’s just formatted not to show it. This way, the year is
always present— either in the dates themselves or at the top of the worksheet.
The formula in cell A1 — =IF(CELL("format”,A4)="D2","Receipts for
"&YEAR(A4),"Receipts")— says that if the formatting in A4 is d-mmm (accord-
ing to the values in Table15-2), display the message with the year; otherwise, just
display Receipts.
Here’s how to use the CELL function:
1. Position the cursor in the cell where you want the results to appear.
2. Type =CELL( to begin the function entry.
3. Type one of the rst argument choices listed in Table15-1.
Make sure to surround it with double quotes (").
4. If you want to tell the function which cell or range to use, type a
comma (,).
5. If you want, type a cell address or the name of a range.
6. Type ) and press Enter.
FIGURE15-1:
Keeping track of
which cell had the
latest entry.
CHAPTER 15 Digging Up the Facts 301
TABLE15-2 Returned Values for the format Argument
Format
Returned Value from
CELL Function
General G
0F0
#,##0 0
0.00 F2
#,##0.00 2
$#,##0_);($#,##0) C0
$#,##0_);[Red]($#,##0) C0-
$#,##0.00_);($#,##0.00) C2
$#,##0.00_);[Red]($#,##0.00) C2-
0% P0
0.00% P2
0.00E+00 S2
# ?/? or ??/?? G
m/d/yy or m/d/yy h:mm or mm/dd/yy D4
d-mmm-yy or dd-mmmm-yy D1
d-mmm or dd-mmm D2
mmm-yy D3
mm/dd D5
h:mm AM/PM D7
h:mm:ss AM/PM D6
h:mm D9
h:mm:ss D8
302 PART 4 Dancing with Data
Getting Information About Excel and
Your Computer System
Excel provides the INFO function to get information about your computer and
about the program itself. INFO takes a single argument that tells the function
what type of information to return. Table15-3 shows how to use the INFO function.
One useful application of the INFO function is counting open worksheets to see if
an excessive amount is open (which could slow down calculations). Bear in mind
that worksheets are only counted in open workbooks. For example, if you have
three workbooks open and each has 100 worksheets, then that’s 300 worksheets
hogging your computer’s memory! This formula uses the NUMFILE choice as the
argument:
=IF(INFO("NUMFILE")>300,"Too many worksheets!","All good,
carry on")
Figure15-3 shows values returned with the INFO function.
Here’s how to use the INFO function:
1. Position the cursor in the cell where you want the results to appear.
2. Type =INFO( to begin the function entry.
FIGURE15-2:
Using CELL and
the format
argument to
display a useful
message.
CHAPTER 15 Digging Up the Facts 303
3. Type one of the argument choices listed in Table15-3.
Make sure to surround it with double quotes (“).
4. Type ) and press Enter.
TABLE15-3 Using INFO to Find Out About Your Computer or Excel
Argument Example Comment
directory =INFO("directory") Returns the path of the current directory. Note that this is not nec-
essarily the same path of the open workbook.
numfile =INFO("numfile") Returns the number of worksheets in all open workbooks. The
function includes worksheets of add-ins, so the number could be
misleading.
origin =INFO("origin") Returns the address of the cell at the top and to the left of the
scrollable area. An A$ prex in front of the cell address is for com-
patibility with Lotus 1-2-3.
osversion =INFO("osversion") Returns the name of the current operating system.
recalc =INFO("recalc") Returns the status of the recalculation mode: Automatic or
Manual.
release =INFO("release") Returns the version number of Excel being run.
system =INFO("system") Returns the name of the operating environment: mac or pcdos.
FIGURE15-3:
Getting facts
about Excel and
the computer
with the INFO
function.
304 PART 4 Dancing with Data
Finding What IS and What IS Not
A handful of IS functions report back a true or false answer about certain cell
characteristics. For example, is a cell blank, or does it contain text? These func-
tions are often used in combination with other functions — typically, the IF
function— to handle errors or other unexpected or undesirable results.
The errors Excel reports are not very friendly. What on earth does #N/A really tell
you? The functions I describe in this section don’t make the error any clearer, but
they give you a way to instead display a friendly message like “Something is
wrong, but I don’t know what it is.”
Table15-4 shows the IS functions and how they’re used. They all return either
True or False, so the table just lists them.
ISERR, ISNA, and ISERROR
Three of the IS functions— ISERR, ISNA, and ISERROR— tell you about an error
(see Table15-5).
TABLE15-4 Using the IS Functions to See What Really Is
Function Comment
=ISBLANK(value) Tells whether a cell is blank.
=ISERR(value) Tells whether a cell contains any error other than #N/A.
=ISERROR(value) Tells whether a cell contains any error.
=ISEVEN(value) Tells whether a number is even.
=ISFORMULA Tells whether the cell contains a formula.
=ISLOGICAL(value) Tells whether the value is logical.
=ISNA(value) Tells whether a cell contains the #N/A error.
=ISNONTEXT(value) Tells whether a cell contains a number or error.
=ISNUMBER(value) Tells whether a cell contains a number.
=ISODD(value) Tells whether a number is odd.
=ISREF(value) Tells whether the value is a reference.
=ISTEXT(value) Tells whether a cell contains text.
CHAPTER 15 Digging Up the Facts 305
Why is #N/A treated separately? It is excluded from being handled with ISERR and
has its own ISNA function. Actually, you can use #N/A to your advantage to avoid
errors. How so? Figure15-4 shows an example that calculates the percentage of
surveys returned for some of Florida’s larger cities. The calculation is simple: Just
divide the returned number by the number sent.
However, errors do creep in. For example, no surveys were sent to Gainesville, yet
99 came back. Interesting! The calculation becomes a division by zero error, which
makes sense. On the other hand, Tallahassee had no surveys sent, but here, the
returned value is the #N/A error, purposely entered. Next, look at column E.In
this column, True or False is returned to indicate whether the calculation, per city,
should be considered an error: Gainesville true, Tallahassee false.
The result true or false appears in column E because all the cells in column E
use the ISERR function. The formula in cell E13, which tests the calculation for
Tallahassee, is =ISERR(D13).
Simply put, D13 displays the #N/A error because its calculation (=C13/B13) uses a
cell with an entered #N/A. The ISERR does not consider #N/A to be an error;
TABLE15-5 Returning Info about Errors
Error Function Comments
ISERR Returns true if the error is anything except the #N/A error. For
example, the #DIV/0! error returns true.
ISNA The opposite of ISERR.It returns true only if the error is #N/A.
ISERROR Returns true for any type of error, including #N/A, #VALUE!, #REF!,
DIV/0!, #NUM!, #NAME?, and #NULL!.
FIGURE15-4:
Using an error to
your advantage.
306 PART 4 Dancing with Data
therefore, E13 returns False. The upshot is that eyeballing column E makes it easy
to distinguish entry and math errors from purposeful agging of certain rows as
having incomplete data.
ISBLANK, ISNONTEXT, ISTEXT,
and ISNUMBER
The ISBLANK, ISNONTEXT, ISTEXT, and ISNUMBER functions tell you what type
of data is in a cell (see Table15-6).
ISBLANK returns true when nothing is in a cell. Using ISBLANK is useful for
counting how many cells in a range are blank. Perhaps you’re responsible for
making sure that 200 employees get their time sheets in every week. You can use
a formula that lets you know how many employees have not yet handed in their
hours.
Such a formula uses ISBLANK along with the IF and SUM functions, like this:
{=SUM(IF(ISBLANK(B5:B26),1,0))}
This formula makes use of an array. See Chapter3 for more information on using
array formulas. Figure15-5 shows how this formula works. In columns A and B
are lists of employees and their hours. The formula in cell A1 reports how many
employees are missing their hours.
ISTEXT returns True when a cell contains any type of text. ISNONTEXT returns
True when a cell contains anything that is not text, including numbers, dates, and
times. The ISNONTEXT function also returns True if the cell contains an error.
TABLE15-6 Returning Info about data in a Cell
Error Function Comments
ISBLANK Returns true if the cell is empty; otherwise, returns false.
ISNONTEXT Returns true if the cell contains anything that is not text: a number, a
date/time, or an error. The function returns true if the cell is blank or
false if the cell contains text or a formula whose result is text.
ISTEXT The opposite of ISNONTEXT: Returns true if the cell contains text or a
formula whose result is text; otherwise, returns false.
ISNUMBER Returns true if the cell contains a number or a formula whose result
is a number; otherwise, returns false.
CHAPTER 15 Digging Up the Facts 307
The ISNUMBER function returns True when a cell contains a number, which can
be an actual number or a number resulting from evaluation of a formula in the
cell. You can use ISNUMBER as an aid to help data entry. Say you designed a work-
sheet that people ll out. One of the questions is age. Most people would type a
numeric value such as 18, 25, 70, and so on. But someone could type the age as
text, such as eighteen, thirty-two, or “none of your business.” An adjacent cell
could use ISNUMBER to return a message about entering the numeric age. The
formula would look something like this:
=IF(ISNUMBER(B3),"","Please enter your age as a number")
Here’s how to use any of the IS functions:
1. Position the cursor in the cell where you want the results to appear.
2. Type one of the IS functions.
For example, type =ISTEXT( to begin the function entry.
3. Type a cell address.
4. Type ) and press Enter.
The result is always True or False.
FIGURE15-5:
Calculating
how many
employees are
missing an entry.
308 PART 4 Dancing with Data
Getting to Know Your Type
The TYPE function tells you what the type of the information is; for example:
»
Number
»
Text
»
A logical value
»
An error
»
An array
In all cases TYPE returns a number:
»
1 is returned for numbers.
»
2 is returned for text.
»
4 is returned for logical values.
»
16 is returned for errors.
»
64 is returned for arrays.
Figure15-6 shows each of these values returned by the TYPE function. Cells B3:B7
contain the TYPE function, with each row looking at the adjacent cell in column
A. The returned value of 64in cell B7 is a little dierent. This indicates an array as
the type. The formula in cell B7 is =TYPE(A7:A9). This is an array of values from
cells A7:A9.
FIGURE15-6:
Getting the type
of the data.
CHAPTER 15 Digging Up the Facts 309
Here’s how to use the TYPE function:
1. Position the cursor in the cell where you want the results to appear.
2. Type =TYPE( to begin the function entry.
3. Type a cell address or click a cell.
4. Type ) and press Enter.
The ERROR.TYPE function returns a number that corresponds to the particular
error in a cell. Table15-7 shows the error types and the returned numbers.
The best thing about the ERROR.TYPE function is that you can use it to change
those pesky errors to something readable! To do this, use the CHOOSE function
along with ERROR.TYPE, like this:
=CHOOSE(ERROR.TYPE(H14),"Nothing here!","You can't divide
by 0","A bad number has been entered","The formula is
referencing a bad cell or range","There is a problem with
the entry","There is a problem with the entered value",
"Something is seriously wrong!")
See Chapter14 for assistance on using the CHOOSE function. This is how you use
the ERROR.TYPE function:
1. Position the cursor in the cell where you want the results to appear.
2. Type =ERROR.TYPE( to begin the function entry.
3. Type a cell address or click a cell.
4. Type ) and press Enter.
TABLE15-7 Getting a Number of an Error
Error Type Returned Number
#NULL! 1
#DIV/0! 2
#VALUE! 3
#REF! 4
#NAME? 5
#NUM! 6
#N/A 7
CHAPTER 16 Writing Home about Text Functions 311
Chapter16
Writing Home about
Text Functions
A
rose is still a rose by any other name. Or maybe not, when you use Excel’s
sophisticated text-manipulation functions to change it into something
else. Case in point: You can use the REPLACE function to change a rose into
a tulip or a daisy, literally!
Did you ever have to work on a list in which people’s full names are in one column,
but you need to use only their last names? You could extract the last names to
another column manually, but that strategy gets pretty tedious for more than a
few names. What if the list contains hundreds of names? This is just one example
of text manipulations that you can do easily and quickly with Excel’s text
functions.
Breaking Apart Text
Excel has three functions that are used to extract part of a text value (often referred
to as a string). The LEFT, RIGHT, and MID functions let you get to the parts of a
text value that their name implies, extracting part of a text value from the left, the
right, or the middle. Mastering these functions gives you the power to literally
break text apart.
IN THIS CHAPTER
»
Assembling, altering, and
formatting text
»
Figuring out the length of text
»
Comparing text
»
Searching for text
312 PART 4 Dancing with Data
How about this? You have a list of codes of inventory items. The rst three char-
acters are the vendor ID, and the other characters are the part ID.You need just
the vendor IDs. How do you do this? Or how do you get the part numbers not
including the vendor IDs? Excel functions to the rescue!
Bearing to the LEFT
The LEFT function lets you grab a specied number of characters from the left
side of a larger string. All you do is tell the function what or where the string is
and how many characters you need to extract.
Figure16-1 demonstrates how the LEFT function isolates the vendor ID in a hypo-
thetical product code list (column A). The vendor ID is the rst three characters in
each product code. You want to extract the rst three characters of each product
code and put them in column B.You put the LEFT function in column B with the
rst argument, specifying where the larger string is (column A) and the second
argument specifying how many characters to extract (three). See Figure16-1 for
an illustration of this worksheet with the LEFT formula visible in the Formula Bar.
(What’s column C in this worksheet? I’ll get to that in the next section.)
FIGURE16-1:
Getting the three
left characters
from a larger
string.
CHAPTER 16 Writing Home about Text Functions 313
What if you ask LEFT to return more characters than the entire original string
contains? No problem. In this case, LEFT simply returns the entire original string.
The same is true for the RIGHT function, explained in the next section.
The LEFT function is really handy and so easy to use. Try it yourself:
1. Position the cursor in the cell where you want the extracted string
displayed.
2. Type =LEFT( to start the function.
3. Click the cell containing the original string or type its address.
4. Type a comma (,).
5. Type a number.
This number tells the function how many characters to extract from the left of
the larger string. If you type a number that is equal to or larger than the
number of characters in the string, the whole string is returned.
6. Type ) and press Enter.
Swinging to the RIGHT
Excel does not favor sides. Because there is a LEFT function, there also is a RIGHT
function. RIGHT extracts a specied number of characters from the right of a
larger string. It works pretty much the same way as the LEFT function.
Column C in Figure16-1, earlier in this chapter, uses the RIGHT function to extract
the right-most four characters from the product codes. Cell C4, for example, has
this formula: =RIGHT(A4,4).
Here’s how to use the RIGHT function:
1. Position the cursor in the cell where you want the extracted string
displayed.
2. Type =RIGHT( to start the function.
3. Click the cell containing the original string or type its address.
4. Type a comma (,).
314 PART 4 Dancing with Data
5. Type a number.
This number tells the function how many characters to extract from the right
of the larger string. If you type a number that is equal to or larger than the
number of characters in the string, the whole string is returned.
6. Type ) and press Enter.
Use LEFT and RIGHT to extract characters from the start or end of a text string.
Use MID to extract characters from the middle.
Staying in the MIDdle
MID is a powerful text-extraction function. It lets you pull out a portion of a larger
string— from anywhere within the larger string. The LEFT and RIGHT functions
allow you to extract from the start or end of a string, but not the middle. MID gives
you essentially complete exibility.
MID takes three arguments: the larger string (or a reference to one), the character
position to start at, and how many characters to extract. Here’s how to use MID:
1. Position the cursor in the cell where you want the extracted string
displayed.
2. Type =MID( to start the function.
3. Click the cell that has the full text entry or type its address.
4. Type a comma (,).
5. Type a number to tell the function which character to start the
extraction from.
This number can be anything from 1 to the full count of characters of the
string. Typically, the starting character position used with MID is greater than 1.
Why? If you need to start at the rst position, you may as well use the simpler
LEFT function. If you type a number for the starting character position that is
greater than the length of the string, nothing is returned.
6. Type a comma (,).
7. Type a number to tell the function how many characters to extract.
If you type a number that is greater than the remaining length of the string, the
full remainder of the string is returned. For example, if you tell MID to extract
characters 2 through 8 of a six-character string, MID returns characters 2
through 6.
8. Type ) and press Enter.
CHAPTER 16 Writing Home about Text Functions 315
Table16-1 shows some examples of how MID works.
Figure16-2 shows how the MID function helps isolate the fourth and fth char-
acters in the hypothetical inventory shown in Figure16-1. These characters could
represent a storage-bin number for the inventory item. The MID function makes
it easy to extract this piece of information from the larger product code.
Finding the long of it with LEN
The LEN function returns a string’s length. It takes a single argument: the string
being evaluated. LEN is often used with other functions, such as LEFT or RIGHT.
TABLE16-1 How MID Works
Example Result
=MID("APPLE",4,2) LE
=MID("APPLE",4,1) L
=MID("APPLE",2,3) PPL
=MID("APPLE",5,1) E
FIGURE16-2:
Using MID to
pull characters
from any position
in a string.
316 PART 4 Dancing with Data
Manipulating text sometimes requires a little math. For example, you may need to
calculate how many characters to isolate with the RIGHT function. A common
conguration of functions to do this is RIGHT, SEARCH, and LEN, like this:
=RIGHT(A1,LEN(A1)-SEARCH(" ",A1))
This calculates the number of characters to return as the full count of characters
less the position where the space is. Used with the RIGHT function, this returns
the characters to the right of the space.
The LEN function is often used with other functions, notably LEFT, RIGHT, and
MID.In this manner, LEN helps determine the value of an argument to the other
function.
Here’s how to use LEN:
1. Position the cursor in the cell where you want the results to appear.
2. Type =LEN( to begin the function.
3. Perform one of these steps:
•
Click a cell that contains text.
•
Type the cell’s address.
•
Type a string enclosed in double quotation marks.
4. Type ) and press Enter.
Putting Text Together with CONCATENATE
The CONCATENATE function pulls multiple strings together into one larger string.
A good use of this is when you have a column of rst names and a column of last
names and need to put the two together to use as full names.
CONCATENATE takes up to 255 arguments. Each argument is a string or a cell
reference, and the arguments are separated by commas. The function does not
insert anything, such as a space, between the strings. If you need to separate the
substrings, as you would with the rst name and last name example, you must
explicitly insert the separator. Figure16-3 makes this clear. You can see that the
second argument to the CONCATENATE function is a space.
CHAPTER 16 Writing Home about Text Functions 317
In Figure16-3, the full names displayed in column C are concatenated from the
rst and last names in columns A and B, respectively. In the function’s argu-
ments, type a space between the references to cells in columns A and B.You type
a space by enclosing a space between double quotation marks, like this: " ".
There is another way to concatenate strings. You can use the ampersand (&) char-
acter instead and skip using CONCATENATE.Another way to create the full names
shown in Figure16-3 is to type the following formula in the target cell: =A3 &
" " & B3. Either method gets the job done. There really is no compelling reason
to use one over the other; it’s up to you, empowered user!
You can give this a whirl on your own. You probably have a list of names some-
where in an Excel workbook. Open that workbook, or at least type rst names and
last names on your own, and then follow these steps:
1. Position the cursor in an empty column, in the same row as the rst text
entry, and type =CONCATENATE( to start the function.
2. Click the cell that has the rst name or type its address.
3. Type a comma (,).
4. Type a space inside double quotation marks.
It should look like this: " ".
5. Type a comma (,).
FIGURE16-3:
Putting strings
together with
CONCATENATE.
318 PART 4 Dancing with Data
6. Click the cell that has the last name or type its address.
7. Type ) and press Enter.
8. Use the ll handle to drag the function into the rows below, as many
rows as there are text entries in the rst column.
You can combine text strings in two ways: Use the CONCATENATE function or use
the ampersand (&) operator.
Changing Text
There must be a whole lot of issues about text. I say that because a whole lot of
functions let you work with text. There are functions that format text, replace text
with other text, and clean text. (Yes, text needs a good scrubbing at times.) There
are functions just for making lowercase letters into uppercase and uppercase let-
ters into lowercase.
Making money
Formatting numbers as currency is a common need in Excel. The Format Cells
dialog box or the Currency Style button in the Number Formatting options of the
Home tab of the Ribbon are the usual places to go to format cells as currency. Excel
also has the DOLLAR function. On the surface, DOLLAR seems to do the same
thing as the similar currency formatting options but has some key dierences:
»
DOLLAR converts a number to text. Therefore, you cannot perform math
on a DOLLAR value. For example, a series of DOLLAR amounts cannot be
summed into a total.
»
DOLLAR displays a value from another cell. As its rst argument, DOLLAR
takes a cell address or a number typed directly in the function. DOLLAR is
handy when you want to preserve the original cell’s formatting. In other
words, you may need to present a value as currency in one location but also
let the number display in its original format in another location. DOLLAR lets
you take the original number and present it as currency in another cell— the
one you place the DOLLAR function in.
»
DOLLAR includes a rounding feature. DOLLAR has a bit more muscle than
the currency style. DOLLAR takes a second argument that species how many
decimal places to display. When negative values are typed for the second
argument, this serves to apply rounding to the digits on the left side of
thedecimal.
CHAPTER 16 Writing Home about Text Functions 319
Figure16-4 shows how the DOLLAR function can display various numeric values
just the way you want. At the bottom of the worksheet is an area of detailed rev-
enues. At the top is a summary that uses DOLLAR.
Unless a cell has been formatted otherwise, you can tell the type of entry by align-
ment. Text aligns to the left; numbers align, to the right.
Specically, the cells in the range C5:D7 use the DOLLAR function to present val-
ues from the detail area and also round them down to no decimals. For example,
cell C5 contains =DOLLAR(G15,0). Table16-2 shows some examples of how the
rounding feature works.
Using DOLLAR is easy. Follow these steps:
1. Position the cursor in the cell where you want the results to appear.
2. Type =DOLLAR( to begin the function entry.
3. Click a cell that contains a number or type a number.
4. Type a comma (,).
FIGURE16-4:
Using DOLLAR to
round numbers
and format them
as currency.
320 PART 4 Dancing with Data
5. Type a number to indicate the number of decimal points to display.
If the number is 0, no decimal points are displayed. Numbers less than 0 force
rounding to occur to the left of the decimal point.
6. Type ) and press Enter.
The DOLLAR function is named DOLLAR in countries that use dollars, such as the
United States and Canada. In versions of Excel designed for countries that use a
dierent currency, the name of the function should match the name of the
currency.
Turning numbers into text
The TEXT function is a bit like the DOLLAR function in that it converts a number
value to text data, but it gives you more formatting options for your results. TEXT
can format numbers as currency, like DOLLAR, but is not limited to this.
The rst TEXT argument is a number or reference to a cell that contains a
number. The second argument is a formatting pattern that tells the function how
to format the number. You can see some formatting patterns in the Custom
category on the Number tab of the Format Cells dialog box (shown in Figure16-5).
Excel lets you create custom formatting patterns so you can present your data
just the way you need to. For example, you can specify whether numbers use a
thousands separator, whether decimal values are always displayed to the third
decimal point, and so on.
TABLE16-2 The Rounding Feature
Example Result
=DOLLAR(1234.56,2) $1,234.56
=DOLLAR(1234.56,1) $1,234.6
=DOLLAR(1234.56,0) $1,235
=DOLLAR(1234.56,-1) $1,230
=DOLLAR(1234.56,-2) $1,200
=DOLLAR(1234.56,-3) $1,000
CHAPTER 16 Writing Home about Text Functions 321
These patterns are created with the use of a few key symbols. A pound sign (#) is
a placeholder for a number— that is, a single digit. Interspersing pound signs
with xed literal characters (such as a dollar sign, a percent sign, a comma, or a
period) establishes a pattern. For example, this pattern— $#,###.#— says to
display a dollar sign in front of the number, to use a comma for a thousands sep-
arator, and to display one digit to the right of the decimal point. Some formatting
options used with the TEXT function are shown in Table16-3. Look up custom
number formatting in Excel Help for more information on custom format pat-
terns, or go to www.microsoft.com and search for guidelines for custom
numberformats.
Figure16-6 shows how the TEXT function is used to format values that are incorpo-
rated into sentences. Column C contains the formulas that use TEXT.For example,
C4 has this formula: ="We spent " & TEXT(B4,"$#,#.#0") & " on " & A4. Cell C8
has this formula: ="We opened the office on " & TEXT(B8,"mmm d, yyyy").
Here’s how to use TEXT:
1. Position the cursor in the cell where you want the results to appear.
2. Type =TEXT( to begin the function entry.
3. Click a cell that contains a number or a date or type its address.
4. Type a comma (,).
FIGURE16-5:
Formatting
options in the
Format Cells
dialog box.
322 PART 4 Dancing with Data
5. Type a quotation mark (") and then type a formatting pattern.
See the Format Cells dialog box (the Custom category of the Number tab) for
guidance.
6. Type a quotation mark (") after the pattern is typed.
7. Type ) and press Enter.
The VALUE function does the opposite of TEXT; it converts strings to numbers
(this is not to say text such as twenty, but numbers that have been formatted as
text). Excel does this by default anyway, so I don’t cover the VALUE function here.
You can look it up in Excel’s Help system if you’re curious about it.
FIGURE16-6:
Using TEXT to
report in a
well-formatted
manner.
TABLE16-3 Formatting Options for the TEXT Function
Format Displays
=TEXT(1234.56,"#.##") 1234.56
=TEXT(1234.56,"#.#") 1234.6
=TEXT(1234.56,"#") 1235
=TEXT(1234.56,"$#") $1235
=TEXT(1234.56,"$#,#") $1,235
=TEXT(1234.56,"$#,#.##") $1,234.56
=TEXT(0.4,"#%") 40%
=TEXT("3/15/2005","mm/dd/yy") 03/15/05
=TEXT("3/15/2005","mm/dd/yyyy") 03/15/2005
=TEXT("3/15/2005","mmm-dd") Mar-15
CHAPTER 16 Writing Home about Text Functions 323
Repeating text
REPT is a nifty function that does nothing other than repeat a string of text. REPT
has two arguments:
»
The string or a reference to a cell that contains text
»
The number of times to repeat the text
REPT makes it a breeze to type a large number of repeating characters. Figure16-7
shows how this works. Cells B14 and B15 contain important summary information.
To make this stand out, a string of asterisks (*) has been placed above and below,
respectively, in B13 and B16. The REPT function was used here, with this formula:
=REPT("*",120). This simple function has removed the drudgery of having to
type 120 asterisks.
Try it out:
1. Position the cursor in the cell where you want the results to appear.
2. Type =REPT( to begin the function entry.
3. Click a cell that contains text or type text enclosed in double quotation
marks.
Typically, you would type a character (such as a period or an asterisk), but any
text will work.
4. Type a comma (,).
5. Type a number to tell the function how many times to repeat the text.
6. Type ) and press Enter.
FIGURE16-7:
Repeating text
with the REPT
function.
324 PART 4 Dancing with Data
Swapping text
Two functions— REPLACE and SUBSTITUTE— replace a portion of a string with
other text. The functions are nearly identical in concept but are used in dierent
situations.
Both REPLACE and SUBSTITUTE replace text within other text. Use REPLACE
when you know the position of the text you want to replace. Use SUBSTITUTE
when you don’t know the position of the text you want to replace.
REPLACE
REPLACE takes four arguments:
»
The target string as a cell reference
»
The character position in the target string at which to start replacing
»
The number of characters to replace
»
The string to replace with (does not have to be the same length as the text
being replaced)
For example, if cell A1 contains the string Our Chicago office has closed., the
formula =REPLACE(A1,5,7,"Dallas") returns the string Our Dallas office has
closed.
Figure 16-8 shows how to use REPLACE with the Inventory Control data rst
shown in the “Breaking Apart Text” section. A new task is at hand. For compati-
bility with a new computer system, you have to modify the product codes in the
inventory data with two dashes between the vendor ID and the internal tracking
number. The original codes are in column A.Use a combination of REPLACE and
LEFT functions to get the job done: =REPLACE(A4, 1, 3, LEFT(A4,3) & "--").
These arguments replace the original three characters in each product code with
the same three characters followed by two dashes. Figure 16-8 shows how
REPLACE alters the product codes. In the gure, the rst three product code char-
acters are replaced with themselves and the dashes. The LEFT function and the
dashes serve as the fourth argument of REPLACE.
CHAPTER 16 Writing Home about Text Functions 325
Keep in mind a couple of points about REPLACE:
»
You need to know where the text being replaced is in the larger text.
Specically, you have to tell the function at what position the text starts and
how many positions it occupies.
»
The text being replaced and the new text taking its place don’t have to
be the same length.
Here’s how to use the REPLACE function:
1. Position the cursor in the cell where you want the result to appear.
2. Type =REPLACE( to begin the function entry.
3. Click a cell that contains the full string of which a portion is to be
replaced.
4. Type a comma (,).
5. Type a number to tell the function the starting position of the text to be
replaced.
6. Type a comma (,).
7. Type a number to tell the function how many characters are to be
replaced.
FIGURE16-8:
Using REPLACE to
change text.
326 PART 4 Dancing with Data
8. Type a comma (,).
9. Click a cell that contains text or type text enclosed in double quotation
marks.
This is the replacement text.
10. Type ) and press Enter.
You can also use REPLACE to delete text from a string. Simply specify an empty
string (" ") as the replacement text.
SUBSTITUTE
Use the SUBSTITUTE function when you don’t know the position in the target
string of the text to be replaced. Instead of telling the function the starting posi-
tion and number of characters (as you do with REPLACE), you just tell it what
string to look for and replace.
SUBSTITUTE takes three required arguments and a fourth optional argument:
»
A reference to the cell that contains the target text string
»
The string within the target string that is to be replaced
»
The replacement text
»
An optional number to tell the function which occurrence of the string to
replace
The fourth argument tells SUBSTITUTE which occurrence of the text to be changed
(the second argument) and actually replaced with the new text (the third argu-
ment). The text to be replaced may appear more than once in the target string. If
you omit the fourth argument, all occurrences are replaced. This is the case in the
rst example in Table 16-4; all spaces are replaced with commas. In the last
example in Table16-4, only the second occurrence of the word two is changed to
the word three.
Try it yourself! Here’s what you do:
1. Position the cursor in the cell where you want the result to appear.
2. Type =SUBSTITUTE( to begin the function entry.
3. Click a cell that contains text or type its address.
This is the full string of which a portion is to be replaced.
4. Type a comma (,).
CHAPTER 16 Writing Home about Text Functions 327
5. Click a cell that contains text or type text enclosed in double quotation
marks.
This is the portion of text that is to be replaced.
6. Type a comma (,).
7. Click a cell that contains text or type text enclosed in double quotation
marks.
This is the replacement text. If you want to specify which occurrence of text to
change, continue to steps 8 and 9; otherwise, go to Step 10.
8. Type a comma (,).
9. Type a number that tells the function which occurrence to apply the
substitution to.
10. Type ) and press Enter.
You can use SUBSTITUTE to remove spaces from text. In the second argument
(what to replace), type a space enclosed in double-quote marks. In the third argu-
ment, type two double-quote marks with nothing between them. This is known as
an empty string.
TABLE16-4 Applying the SUBSTITUTE Function
Example Returned String Comment
=SUBSTITUTE("apple banana cherry
fig", " ",",")
apple,banana,cherry,g All spaces are replaced with
commas.
=SUBSTITUTE("apple banana cherry
fig", " ",",",1)
apple,banana cherry g The rst space is replaced
with a comma. The other
spaces remain as they are.
=SUBSTITUTE("apple banana cherry
fig", " ",”,",3)
apple banana cherry,g The third space is replaced
with a comma. The other
spaces remain as they are.
=SUBSTITUTE("There are two cats
and two birds.","two","three")
There are three cats and
three birds.
Both occurrences of two are
replaced with three.
=SUBSTITUTE("There are two cats
and two birds.","two","three",2)
There are two cats and
three birds.
Only the second occurrence
of two is replaced with three.
328 PART 4 Dancing with Data
Giving text a trim
Spaces have a way of sneaking in and ruining your work. The worst thing is that
you often can’t even see them! When the space you need to remove is at the begin-
ning or end of a string, use the TRIM function to remove them. The function sim-
ply clips any leading or trailing spaces from a string. It also removes extra spaces
from within a string; a sequence of two or more spaces is replaced by a single
space.
Figure16-9 shows how this works. In column A is a list of names. Looking closely,
you can see that some unwanted spaces precede the names in cells A5 and A10.
Column B shows the correction using TRIM. Here is the formula in cell
B5: =TRIM(A5).
TRIM takes just one argument: the text to be cleaned of leading and trailing
spaces. Here’s how it works:
1. Position the cursor in the cell where you want the result to appear.
2. Type =TRIM( to begin the function entry.
3. Click a cell that contains the text that has leading or trailing spaces, or
type the cell address.
4. Type ) and press Enter.
FIGURE16-9:
Removing spaces
with the TRIM
function.
CHAPTER 16 Writing Home about Text Functions 329
Be on the lookout: Although you generally use it to remove leading and trailing
spaces, TRIM removes extra spaces in the middle of a string. If two or more spaces
are next to each other, TRIM removes the extra spaces and leaves one space in
place.
This is usually a good thing. Most times, you don’t want extra spaces in the mid-
dle of your text. But what if you do? Table16-5 shows a couple of alternatives to
remove a leading space, if it is there, without aecting the middle of the string.
Making a case
In school, you were taught to use an uppercase letter at the start of a sentence as
well as for proper nouns. But that was a while ago, and now the brain cells are a
bit fuzzy. Lucky thing Excel has a way to help x case, er Case, um CASE— well,
you know what I mean.
Three functions alter the case of text: UPPER, LOWER, and PROPER. All three
functions take a single argument — the text that will have its case altered.
Table16-6 shows a few examples.
TABLE16-5 Removing Spaces
Formula to Remove Leading Space Comment
=IF(LEFT(E10,1)=" ",SUBSTITUTE
(E10," ","",1), E10)
If a space is found in the rst position, substitute an empty
string; otherwise, just return the original string.
=IF(LEFT(E10,1)=" ",RIGHT(E10,LEN
(E10)-1), E10)
If a space is found in the rst position, return the right side of
the string, less the rst position. (See the section on LEN, ear-
lier in this chapter.)
TABLE16-6 Changing Text Case
Formula Result
=LOWER("The Cow Jumped Over The Moon") the cow jumped over the moon
=UPPER("the cow jumped over the moon") THE COW JUMPED OVER THE MOON
=PROPER("the cow jumped over the moon") The Cow Jumped Over The Moon
330 PART 4 Dancing with Data
Try this:
1. Type a sentence in a cell.
Any old sentence will do, but don’t make any letters uppercase. For example,
type excel is great or computers give me a headache.
2. Position the cursor in an empty cell.
3. Type =UPPER( to start the function.
4. Click the cell that has the sentence or type its address.
5. Type ) and press Enter.
6. In another empty cell, type =PROPER( to start the function.
7. Click the cell that has the sentence or type its address.
8. Type ) and press Enter.
You should now have two cells that show the sentence with a case change.
One cell has the sentence in uppercase; the other cell has the sentence, in
proper case.
Perhaps you noticed another possibility that needs to be addressed. What about
when just the rst word needs to start with an uppercase letter and the rest of the
string is all lowercase? Some people refer to this as sentence case. You can create
sentence case by using the UPPER, LEFT, RIGHT, and LEN functions. (LEN is
explained earlier in this chapter.) With the assumption that the text is in cell B10,
here is how the formula looks:
=UPPER(LEFT(B10,1)) & RIGHT(B10,LEN(B10)-1)
In a nutshell, the UPPER function is applied to the rst letter, which is isolated
with the help of the LEFT function. This result is concatenated with the remainder
of the string. You know how much is left by using LEN to get the length of the
string and using the RIGHT function to get all the characters from the right, less
one. This type of multiuse function work takes a bit of getting used to.
Comparing, Finding, and Measuring Text
Excel has many functions that manipulate text, but sometimes you just need to nd
out about the text before you do anything else! A handful of functions determine
whether text matches other text, let you nd text inside other text, and tell you how
long a string is. These functions are passive— that is, they do not alter text.
CHAPTER 16 Writing Home about Text Functions 331
Going for perfection with EXACT
The EXACT function lets you compare two strings of text to see whether they’re
the same. The function takes two arguments— the two strings of text — and
returns a true or false value. EXACT is case sensitive, so two strings that contain
the same letters but with diering case produce a result of false. For example,
Apple and APPLE are not identical.
EXACT is great for nding changes in data. Figure 16-10 shows two lists of
employees, one for each year, in columns A and B.Are they identical? You could
spend a number of minutes staring at the two lists. (That would give you a head-
ache!) Or you can use EXACT.The cells in column C contain the EXACT function,
used to check column A against column B.The returned values are true for the
most part. This means there is no change.
A few names are dierent in the second year. Marriage, divorce, misspellings—
the mismatched data could be because of any of these. EXACT returns false for
these names, which means they aren’t identical in the two lists and should be
checked manually.
Here’s how you use EXACT:
1. Position the cursor in the cell where you want the results to appear.
2. Type =EXACT( to begin the function entry.
3. Click a cell that contains text or type its address.
FIGURE16-10:
Comparing
strings with the
EXACT function.
332 PART 4 Dancing with Data
4. Type a comma (,).
5. Click another cell that has text or type its address.
6. Type ) and press Enter.
If you get a true result with EXACT, the strings are identical. A false result means
they’re dierent.
What if you want to compare strings without regard to case? In other words, APPLE
and apple would be considered the same. Excel does not have a function for this,
but the result is easily obtained with EXACT and UPPER.The idea is to convert
both strings to uppercase and compare the results:
=EXACT(UPPER("APPLE"), UPPER("apple"))
You could just as well use LOWER here.
Finding and searching
Two functions, FIND and SEARCH, work in a quite similar fashion. A couple of
dierences are key to guring out which to use. Both FIND and SEARCH nd one
string inside a larger string and tell you the position at which it was found
(or produce #VALUE if it is not found). The dierences are shown in Table16-7.
FIND
FIND takes three arguments:
»
The string to nd
»
The larger string to search in
»
The position in the larger string to start looking at; this argument is optional
If the third argument is left out, the function starts looking at the beginning of the
larger string. Table16-8 shows some examples.
TABLE16-7 Comparing FIND and SEARCH
FIND SEARCH
Case-sensitive. It will not, for example, nd At
inside heat.
Not case-sensitive.
You cannot use the wildcards * and ?. You can use the wildcards * and ?.
CHAPTER 16 Writing Home about Text Functions 333
In the rst example using FIND, an error is returned. The #VALUE! error is
returned if the text cannot be found. Birthday is not the same as birthday, at
least to the case-sensitive FIND function.
SEARCH
The SEARCH function takes the same arguments as FIND.The two common wild-
cards you can use are the asterisk (*) and the question mark (?). An asterisk tells
the function to accept any number of characters (including zero characters).
Aquestion mark tells the function to accept any single character. It is not uncom-
mon to see more than one question mark together as a wildcard pattern. Table16-9
shows several examples.
Back in Figure16-3, I show you how to concatenate rst and last names. What if
you have full names to separate into rst names and last names? SEARCH to the
rescue! (Does that make this a search-and-rescue mission?) Figure16-11 shows
how the SEARCH, LEFT, RIGHT, and ISERROR functions work together to turn
names into individual rst and last names.
Isolating the rst name from a full name is straightforward. You just use LEFT to
get characters up to the rst space. The position of the rst space is returned from
the SEARCH function. Here is how this looks:
=LEFT(A3,SEARCH(" ",A3)-1)
Getting the last names is just as simple— not! When the full name has only rst
and last names (no middle name or initials), you need SEARCH, RIGHT, and LEN,
like this:
=RIGHT(A3,LEN(A3)-SEARCH(" ",A3))
TABLE16-8 Finding One String inside Another String
Value in Cell A1 Function Result
Happy birthday to you =FIND("Birthday",A1) #VALUE!
Happy birthday to you =FIND("birthday",A1) 7
Happy birthday to you =FIND("y",A1) 5
Happy birthday to you =FIND("y",A1,10) 14
334 PART 4 Dancing with Data
However, this does not work for middle names or initials. What about Franklin
D.Roosevelt? If you rely on the last name being after the rst space, the last name
becomes D.Roosevelt. An honest mistake, but you can do better. What you need is
a way to test for the second space and then return everything to the right of that
space. There are likely a number of ways to do this.
Here is what you see in column C, in Figure16-11:
=IF(ISERROR(SEARCH(" ",RIGHT(A3,LEN(A3)-SEARCH(" ",A3)))),
RIGHT(A3,LEN(A3)-SEARCH(" ",A3)),RIGHT(A3,LEN(A3)-SEARCH
(" ",A3,SEARCH(" ",A3)+1)))
TABLE16-9 Using the SEARCH Function
Value
in Cell A1 Function Result Comment
Happy
birthday to
you
=SEARCH("Birthday",A1) 7birthday starts in position 7.
Happy
birthday to
you
=SEARCH("y??",A1) 5The rst place where a y is followed by any two
characters is at position 5. This is the last letter in
Happy, a space, and the rst letter in birthday.
Happy
birthday to
you
=SEARCH("yo?",A1) 19 The rst place where yo is followed by any single
character is the word you.
Happy
birthday to
you
=SEARCH("b*d",A1) 7The search pattern is the letter b, followed by any
number of characters, followed by the letter d. This
starts in position 7.
Happy
birthday to
you
=SEARCH("*b",A1) 1The asterisk says search for any number of charac-
ters before the letter b. The start of characters
before the letter b is at position 1. Using an asterisk
at the start is not useful. It will either return a 1 or
an error if the xed character(s) (the letter b in this
example) is not in the larger text.
Happy
birthday to
you
=SEARCH("t*",A1) 10 The asterisk says search for any number of charac-
ters after the letter t. Because the search starts with
a xed character, its position is the result. The
asterisk serves no purpose here.
Happy
birthday to
you
=SEARCH("t",A1,12) 16 Finds the position of the rst letter t, starting after
position 12. The result is the position of the rst let-
ter in the word to. The letter t in birthday is ignored.
CHAPTER 16 Writing Home about Text Functions 335
Admittedly, it’s a doozy. But it gets the job done. Here is an overview of what this
formula does:
»
It’s an IF function and therefore tests for either true or false.
»
The test is if an error is returned from SEARCH for trying to nd a space to the
right of the rst space:
ISERROR(SEARCH(" ",RIGHT(A3,LEN(A3)-SEARCH(" ",A3))))
»
If the test is true, there is no other space. This means there is no middle initial,
so just return the portion of the name after the rst space:
RIGHT(A3,LEN(A3)-SEARCH(" ",A3))
»
If the test is false, there is a second space, and the task is to return the portion
of the string after the second space. SEARCH tells both the position of the rst
space and the second space. This is done by nesting one SEARCH inside the
other. The inner SEARCH provides the third argument— where to start
looking from. A 1 is added so the outer SEARCH starts looking for a space one
position after the rst space:
RIGHT(A3,LEN(A3)-SEARCH(" ",A3,SEARCH(" ",A3)+1))
Your eyes have probably glazed over, but that’s it!
The monster formula isolates last names from full names that include a middle
initial. A task for you to try, if you have any working brain cells left, is to write a
formula that isolates the middle initial, if there is one. Here’s how to use FIND or
SEARCH:
1. Position the cursor in the cell where you want the results to appear.
2. Type =FIND( or =SEARCH( to begin the function entry.
FIGURE16-11:
Splitting names
apart.
336 PART 4 Dancing with Data
3. Type a string of text that you want in a larger string, enclosed with
double quotation marks, or click a cell that contains the text.
4. Type a comma (,).
5. Click a cell that contains the larger text or type its address.
If you want the function to begin searching at the start of the larger string, go
to Step 7. If you want to have the function begin the search in the larger string
at a position other than 1, go to Step 6.
6. Type a comma (,) and the position number.
7. Type ) and press Enter.
CHAPTER 17 Playing Records with Database Functions 337
Chapter17
Playing Records with
Database Functions
Believe it or not, an Excel worksheet has the same structure as a database
table. A database table has elds and records; an Excel worksheet has col-
umns and rows. Same thing. Given this fact, why not ask questions of, or
query, your information in much the same way as you do with a database?
In this chapter, I tell you how to use Excel’s database functions to get quick
answers from big lists. Say you have a client list on a worksheet— name, address,
that sort of thing. You want to know how many clients are in NewYork. You may
think about sorting your list by state and then counting the number of rows. For-
get it. That’s the old way! In this chapter, I show you how to do this sort of thing
with a single function.
IN THIS CHAPTER
»
Understanding an Excel database
structure
»
Figuring out how criteria work
»
Adding, averaging, and counting
database records
»
Testing for duplicate records
338 PART 4 Dancing with Data
Putting Your Data into a
Database Structure
To use the database functions, you need to put your data into a structured format.
Excel is very exible. Usually, you put data wherever you want. But to make the
best of the database functions, you need to get your data into a contiguous area of
rows and columns. Each row is a record, and each column is a eld. The top row
contains labels that identify the elds.
Figure17-1 shows a database in a worksheet. This example is a list of students (by
ID number) and their classes, teachers, and grades. Each student occupies a
row—in other words, a record— in the database. Each of the four elds— Student
ID, Class, Teacher, and Final Grade— is in one column and is identied by a label
in the top row.
The data in the worksheet in Figure17-1 is really just normal data. There is noth-
ing special about it. However, the data sits in organized rows and columns, mak-
ing it ready for working with Excel’s database functions:
»
Each column is a eld that holds one particular item of data, such as Student
ID or Class. It must contain no other data.
FIGURE17-1:
Using a database
to store student
information.
CHAPTER 17 Playing Records with Database Functions 339
»
Each row contains one record. In this example, a record is the data for one
student.
»
The top row of the database contains labels that identify the elds.
This sample data is used in this chapter to demonstrate the database functions. Of
course, you can have a database in Excel and never use the database functions, but
you have a lot more power at your ngertips if you do use them.
Working with Database Functions
The database functions all work in basically the same way. They perform some
calculation on a specied eld for those records that meet specied criteria. For
example, you can use a database function to calculate the average nal grade for
all students in Accounting 101.
All database functions use the following three arguments:
»
The database range: This argument tells the function where the database is.
You type it by using cell addresses (for example, A1:D200) or a named range
(for example, Students). The range must include all records, including the top
row of eld names.
»
The eld: You must tell a database function which eld to operate on. You
can’t expect it to gure this out by itself! You can type either the column
number or the eld name. A column number, if used, is the number of the
column oset from the rst column of the database area. In other words, if a
database starts in column C, and the eld is in column E, the column number
is 3, not 5. If a heading is used, put it inside a set of double quotation marks.
Database functions calculate a result based on the values in this eld. Just
how many values are used depends on the third argument: the criteria.
»
The criteria: This tells the function where the criteria are located; it is not
thecriteria per se. The criteria tell the function which records to use in its
calculation. You set up the criteria in a separate part of the worksheet, apart
from the database area. This area’s address is passed to the database
function. Criteria are explained in detail throughout the chapter.
Establishing your database
All database functions take a database reference as the rst argument. The data-
base area must include headers (eld names) in the rst row. In Figure 17-1,
340 PART 4 Dancing with Data
earlier in this chapter, the rst row uses Student ID, Class, Teacher, and Final
Grade as headers to the information in each respective column.
A great way to work with the database functions is to name the database area and
then type the name, instead of the range address, in the function.
To set up a name, follow these steps:
1. Select the entire database area.
Make sure the top row has headers and is included in the selection.
2. Click the Formulas tab (at the top of the Excel window).
3. Click Dene Name in the Dened Names area.
The New Name dialog box appears, with the range address set in the Refers
To box.
4. Type a name in the Name Box (or use the suggested name).
5. Click OK to close the dialog box.
Later, if records are added to the bottom of the database, you have to redene the
named area’s range to include the new rows. You can do this as follows:
1. Click the Name Manager button on the Excel Formulas tab.
The Name Manager dialog box appears.
2. Click the name in the list you want to redene.
3. Click the Edit button in the dialog box.
Excel opens the Edit Name dialog box, shown in Figure17-2, with information
about the selected range.
FIGURE17-2:
Updating the
reference to a
named area.
CHAPTER 17 Playing Records with Database Functions 341
4. Change the reference in the Refers To box.
You can use the small square button to the right of the Refers To box to dene
the new reference by dragging the mouse pointer over it. Clicking the small
square button reduces the size of the Edit Name dialog box and allows you
access to the worksheet. When you are done dragging the mouse over the new
worksheet area, press Enter to get back to the Edit Name dialog box.
5. Click OK to save the reference change and close the dialog box.
6. Click Close.
If you add records to your database range by inserting new rows somewhere in the
middle, rather than adding them on at the end, Excel automatically adjusts the
reference to the named range.
Establishing the criteria area
As I mention earlier, the criteria are not part of the database function arguments
but are somewhere in the worksheet and then referenced by the function. The
criteria area can contain a single criterion, or it can contain two or more criteria.
Each individual criterion is structured as follows:
»
In one cell, type the eld name (header) of the database column that the
criterion will apply to.
»
In the cell below, type the value that the eld data must meet.
Figure17-3 shows the student database with a criteria area to the right of the
database. There are places to put criteria for the Class, Teacher, and Final Grade.
In the example, a criterion has been set for the Class eld. This criterion forces the
database function to process only records (rows) where the Class is Accounting
101. Note, though, that a criterion can be set for more than one eld. In this exam-
ple, the Teacher and Final Grade criteria have been left blank so they don’t aect
the results.
FIGURE17-3:
Selecting criteria
to use with a
database
function.
342 PART 4 Dancing with Data
The DAVERAGE function has been typed into cell F8 and uses this criteria range.
The three arguments are in place. The name Students tells the function where the
database is, the Final Grade eld (column) is where the function nds values to
calculate the average, and the criteria are set to the worksheet range that has cri-
teria that tell the function to use only records where the Class is Accounting 101—
in other words, F2:H3. The entry in cell F8 looks like this:
=DAVERAGE(Students,"Final Grade",F2:H3)
Why does this function refer to F2:H3 as the criteria range when the only dened
criterion is located in the range F2:F3? It’s a matter of convenience. Because cells
G3 and H3in the criteria range are blank, the Teacher and Final Grade elds are
ignored by a database function that uses this criteria range. However, if you want
to type a criterion for one of those elds, just type it in the appropriate cell; there
is no need to edit the database function arguments. What about assigning a name
to the criteria area and then using the name as the third argument to the database
function? That works perfectly well, too.
Whether you use a named area for your criteria or simply type the range address,
you must be careful to specify an area that includes all the criteria but does not
include any blank rows or columns. If you do, the database function’s results will
be incorrect.
Here’s how you type any of the database functions. This example uses the DSUM
function, but the instructions are the same for all the database functions; just use
the one that performs the desired calculation. Follow these steps:
1. Import or create a database of information in a worksheet.
The information should be in contiguous rows and columns. Be sure to use
eld headers.
2. Optionally, use the New Name dialog box to give the database a name.
To name your database, see the section “Establishing your database” earlier in
this chapter.
3. Select a portion of the worksheet to be the criteria area, and then add
headers to this area that match the database headers.
You have to provide criteria headers only for database elds that criteria are
applied to. For example, your database area may have ten elds, but you need
to dene criteria to three elds. Therefore, the criteria area can be three
columns wide.
4. Position the cursor in the cell where you want the results to appear.
This cell must not be in the database area or the criteria area.
CHAPTER 17 Playing Records with Database Functions 343
5. Type =DSUM( to begin the function entry.
6. Type the database range or a name, if one is set.
7. Type a comma (,).
8. Type either of the following:
•
The header name, in quotation marks, of the database eld that the
function should process
•
The column number
9. Type a comma (,).
10. Type the range of the criteria area.
11. Type ) and press Enter.
Fine-Tuning Criteria with AND and OR
Excel’s database functions would not be of much use if you could not create fairly
sophisticated queries. A few common types of queries follow:
»
Records that match two or more individual criteria
»
Records that match any one of several criteria
»
Values that fall within a specied range of values
To nd records that match two or more criteria, place the criteria in adjacent col-
umns in the criteria area. Continuing with the database of student grades, the
criteria area shown in Figure17-4 matches records where the Class eld contains
Accounting 101 and the Teacher eld contains Mr. Harris. This is called an AND
criterion.
To match records that meet any one of several criteria, place the individual criteria
in two or more rows below the eld name. Figure17-5 shows a criteria range that
matches all records where the Class eld contains either Accounting 101 or English
Literature. This is called an OR criterion.
FIGURE17-4:
Finding records
that match two
criteria.
344 PART 4 Dancing with Data
To combine AND with OR in a criteria range, use two or more columns and two or
more rows. Figure17-6 shows a criteria range that nds all records where Class is
Accounting 101 and Teacher is either Mr. Harris or Mr. Richards.
To dene a criterion that uses ranges of values, use these numerical comparison
operators:
»
< for less than
»
> for greater than
»
<= for less than or equal to
»
>= for greater than or equal to
Of course, you can apply these to elds with numerical values. Figure17-7 shows
two criteria areas. The upper one matches all records in which Final Grade is 90 or
greater. The lower one matches all records in which Final Grade is equal to or
greater than 80 and less than 90.
FIGURE17-5:
Finding records
that match any
one of two or
more criteria.
FIGURE17-6:
Combining AND
and OR criteria.
FIGURE17-7:
Dening
numerical range
criteria.
CHAPTER 17 Playing Records with Database Functions 345
Adding Only What Matters with DSUM
The DSUM function lets you sum numbers in a database column for just those
rows that match the criteria you specify. For example, take a database that con-
tains data on individual sale amounts for salespeople. The database range is
named Sales. You want to calculate total sales for each of the three sales represen-
tatives. Figure17-8 shows how this is done. Three criteria areas are dened in
D2:D3, E2:E3, and F2:F3. The DSUM function is typed in cells E8:E10. The formula
in cell E8 is
=DSUM(SALES, "Sale Amount", D2:D3)
The functions typed in E9 and E10 are identical except for referencing a dierent
criteria range. The results show clearly that Amy is the sales leader.
Going for the Middle with DAVERAGE
The DAVERAGE function lets you nd the average, or mean, of a eld for just the
rows that match the criteria. For this example, you return to the student database.
Figure17-9 shows a worksheet in which the average grade for each course has
been calculated by DAVERAGE.For example, cell G22 shows the average grade for
Masters of Philosophy. Here is the formula:
=DAVERAGE(Students,"Final Grade",F14:G15)
FIGURE17-8:
Calculating the
sum of sales with
the DSUM
function.
346 PART 4 Dancing with Data
Each calculated average uses a dierent criteria area. Each area lters the result
by a particular course. In all cases, the criteria area for the Teacher is left blank
and, therefore, has no eect on the results.
For the sake of comparison, DAVERAGE is also used in cell G24 to show the overall
average for all courses. Because a criterion is a required function argument, the
calculation in cell G24 is set to look at an empty cell. None of the Class criteria cells
is free, so the function looks to the Teacher criterion in cell G3. Because this cell
has no particular teacher typed as a criterion, all of the records in the database are
used to create this average— just what you want. Here is the formula in cell G24:
=DAVERAGE(Students,"Final Grade",G2:G3)
It doesn’t matter which eld header you use in the criterion when you’re getting
a result based on all records in a database. What does matter is that there is no
actual criterion below the header.
FIGURE17-9:
Calculating the
average grade for
each course.
CHAPTER 17 Playing Records with Database Functions 347
Counting Only What Matters
with DCOUNT
The DCOUNT function lets you determine how many records in the database
match the criteria.
Figure17-10 shows how DCOUNT can determine how many students took each
course. Cells G18:G22 contain formulas that count records based on the criterion
(the Class) in the associated criteria sections. Here is the formula used in cell G20,
which counts the number of students in Calculus 101:
=DCOUNT(Students,"Final Grade",F8:G9)
Note that DCOUNT requires a column of numbers to count. Therefore, the Final
Grade heading is put in the function. Counting on Class or Teacher would result in
zero. Using a column that specically has numbers may seem a little odd. The
function is not summing the numbers; it just counts the number of records. But
what the heck? It works.
Now take this a step further. How about counting the number of students who got
a grade of 90 or better in any class? How can this be done? This calculation requires
a dierent criterion — one that selects all records where Final Grade is 90 or
FIGURE17-10:
Calculating
the number
of students in
each course.
348 PART 4 Dancing with Data
greater. Figure 17-11 shows a worksheet with this criterion and the calculated
result shown.
The result in cell F6 concatenates— that is, combines but does not add— the
answer from the DCOUNT function with some text. The formula looks like this:
=DCOUNT(Students,"Final Grade",F2:F3) & " students received a 90
or better."
The criterion specically states to use all records where the Final Grade is greater
than 89 (>89). You can specify >=90 with the exact same result.
Finding Highest and Lowest
with DMIN and DMAX
The DMIN and DMAX functions nd the minimum or maximum value, respec-
tively, in a database column, for just the rows that match the criteria. Figure17-12
shows how these two functions can nd the highest and lowest grades for English
Literature.
The formulas in cells F8 and F10 are practically identical. Here is the formula in
cell F8:
="The highest grade in " & $F$3 & " is " & DMAX(Students,"Final
Grade",$F$2:$F$3)
FIGURE17-11:
Calculating the
number of
students who
earned a grade of
90 or better.
CHAPTER 17 Playing Records with Database Functions 349
Finding Duplicate Values with DGET
DGET is a unique database function. It does not perform a calculation but checks
for duplicate entries. The function returns one of three values:
»
If one record matches the criterion, DGET returns the criterion.
»
If no records match the criterion, DGET returns the #VALUE! error.
»
If more than one record matches the criterion, DGET returns the #NUM! error.
By testing to see whether DGET returns an error, you can discover problems with
your data. Perhaps you suspect that a student has registered twice for a specic
class. If this is true, two records will have the same Student ID and Class.
Figure17-13 shows how to check whether student NR5090 is typed more than
once for Calculus 101. If there is more than one record, DGET returns an error. Cell
F5 contains a formula that nests the DGET function inside the ISERROR function;
all that is inside the IF function. If DGET returns an error, return one message; if
DGET does not return an error, return a dierent message. Here is the formula:
=IF(ISERROR(DGET(Students,"Student ID",F2:G3)),F3 & " has
duplicate records", F3 & " has one record")
FIGURE17-12:
Calculating the
highest and
lowest grades for
a specied class.
350 PART 4 Dancing with Data
Being Productive with DPRODUCT
DPRODUCT multiplies values that match the criterion in a database. This is
powerful but it is also able to produce results that are not the intention. In other
words, it’s one thing to add and derive a sum. That is a common operation on a set
of data. Looking back at Figure17-8, you can see that the total sales for Jack Ben-
net, $79,134, are the sum of three amounts: $43,234, $12,450, and $23,450. If
multiplication were applied to the three amounts, the answer (the product) would
be $12,622,274,385,000. Oops! That’s over 12 trillion dollars!
DPRODUCT multiplies and, therefore, is not likely to be used as often as a function
like DSUM, but when you need to multiply items in a database, DPRODUCT is a
tool of choice.
Figure17-14 shows a situation in which DPRODUCT is productive. The database
area contains shirts. For each shirt size, there are two rows: the price per shirt and
the number of shirts that are packed in a carton. The cost for a carton of shirts is,
therefore, the product of the price per shirt times the number of shirts. There are
four shirt sizes, each with its own price and carton count.
To make sure that you work with just one size per use of DPRODUCT, four criteria
areas are set up— one for each size. Any single criteria area has the Shirt Size
heading and the actual shirt size, such as Medium. For example, D8:D9 contains
the criteria for medium-size shirts.
Four cells each contain DPRODUCT, and within each cell, the particular criteria
area is used. For example, cell E18 has this formula:
=DPRODUCT(A1:C9,"Value",D8:D9)
FIGURE17-13:
Using DGET to
test for duplicate
records in a
database.
CHAPTER 17 Playing Records with Database Functions 351
The database range is A1:C9. Value is the eld the function looks in for values to
multiply, and the multiplication occurs on values for which the shirt size matches
the criteria.
A worksheet set up like the one shown in Figure17-14 is especially useful when
new data are occasionally pasted into the database area. The set of DPRODUCT
functions will always provide the products based on whatever data are placed in
the database area. This particular example of DPRODUCT shows how to work with
data in which more than one row pertains to an item. In this case, each shirt size
has a row showing the price per shirt and a second row showing the number of
shirts that t in a carton.
FIGURE17-14:
Calculating the
total costs of
cartons lled with
shirts.
5
The Part of Tens
IN THIS PART ...
Discover ten tips for working with formulas.
Find ten ways to get fancy with Excel.
Use ten really cool functions.
CHAPTER 18 Ten Tips for Working with Formulas 355
Chapter18
Ten Tips for Working
with Formulas
Several elements can help you be as productive as possible when writing and
correcting formulas. You can view all your formulas at once and correct
errors one by one. You can use add-in wizards to help write functions. You
can even create functions all on your own!
Master Operator Precedence
One of the most important factors in writing formulas is getting the operators
correct, and I do not mean telephone-company operators. This has to do with
mathematical operators— you know, little details such as plus signs, and multi-
plication signs, and where the parentheses go. Operator precedence— the order in
which operations are performed— can make a big dierence in the result. You
have an easy way to keep your operator precedence in order. All you have to
remember is “Please excuse my dear Aunt Sally.”
IN THIS CHAPTER
»
Making sure the order of operators
is correct
»
Viewing and xing formulas
»
Referencing cells and using names
»
Setting the calculation mode
»
Using conditional formatting and
data validation
»
Writing your own functions
356 PART 5 The Part of Tens
No, I have not lost my mind! This phrase is a mnemonic for the following:
Parentheses
Exponents
Multiplication
Division
Addition
Subtraction
Thus, parentheses have the rst (highest) precedence, and subtraction has the last
precedence. Well, to be honest, multiplication has the same precedence as divi-
sion, and addition has the same precedence as subtraction, but you get theidea!
For example, the formula =1+2*15 equals 31. If you think it should equal 45, you’d
better go visit your aunt! The answer equals 45 if you include parentheses, such as
this: =(1+2)*15.
Getting the order of the operators correct is critical to the well-being of your
worksheet. Excel generates an error when the numbers of open and closed paren-
theses do not match, but if you mean to add two numbers before the multiplica-
tion, Excel does not know that you simply left the parentheses out!
A few minutes of refreshing your memory on operator order can save you a lot of
headaches down the road.
Display Formulas
In case you haven’t noticed, it’s kind of hard to view your formulas without acci-
dentally editing them. That’s because any time you are in “edit” mode and the
active cell has a formula, the formula may incorporate the address of any other
cell you click. This totally messes things up.
Wouldn’t it be easy if you could just look at all your formulas? There is a way! It’s
simple. Click File at the top left of the Excel workspace, click Options, click the
Advanced tab, and then scroll down to the Display options for this worksheet sec-
tion (see Figure18-1).
CHAPTER 18 Ten Tips for Working with Formulas 357
Notice the Show Formulas in Cells Instead of Their Calculated Results check box.
This box tells Excel that for any cells that have formulas to display the formula
itself instead of the calculated result. Figure18-2 shows a worksheet that displays
the formulas. To return to normal view, repeat these steps and deselect the option.
This option makes it easy to see what all the formulas are!
You can accidentally edit functions even when you have selected the Show Formu-
las option. Be careful clicking around the worksheet.
FIGURE18-1:
Setting options.
FIGURE18-2:
Viewing formulas
the easy way.
358 PART 5 The Part of Tens
Fix Formulas
Suppose that your worksheet has some errors. Don’t panic! It happens to even the
savviest users, and Excel can help you gure out what’s going wrong. On the For-
mulas tab in the Formula Auditing section is the Error Checking button. Clicking
the button displays the Error Checking dialog box, as shown in Figure18-3. That
is, the dialog box appears if your worksheet has any errors. Otherwise, it just pops
up a message that the error check is complete. It’s that smart!
When there are errors, the dialog box appears and sticks around while you work
on each error. The Next and Previous buttons let you cycle through all the errors
before the dialog box closes. For each error it nds, you choose what action totake:
»
Help on This Error: This leads to the Help system and displays the topic for
the particular type of error.
»
Show Calculation Steps: The Evaluate Formula dialog box opens, and you
can watch step by step how the formula is calculated. This lets you identify the
particular step that caused the error.
»
Ignore Error: Maybe Excel is wrong. Ignore the apparent error.
»
Edit in Formula Bar: This is a quick way to x the formula yourself if you don’t
need any other help.
The Error Checking dialog box also has an Options button. Clicking the button
opens the Formulas tab of the Excel Options dialog box. On the Formulas tab, you
can select settings and rules for how errors are recognized and triggered.
FIGURE18-3:
Checking for
errors.
CHAPTER 18 Ten Tips for Working with Formulas 359
Use Absolute References
If you are going to use the same formula for a bunch of cells, such as those going
down a column, the best method is to write the formula once and then drag it
down to the other cells by using the ll handle. The problem is that when you drag
the formula to new locations, any relative references change.
Often, this is the intention. When there is one column of data and an adjacent
column of formulas, typically, each cell in the formula column refers to its neigh-
bor in the data column. But if the formulas all reference a cell that is not adjacent,
the intention usually is for all the formula cells to reference an unchanging cell
reference. Get this to work correctly by using an absolute reference to the cell.
To use an absolute reference to a cell, use the dollar sign ($) before the row num-
ber, before the column letter, or before both. Do this when you write the rst
formula, before dragging it to other cells, or you will have to update all the
formulas.
For example, don’t write this:
=A4*(B4+A2)
Write it this way instead:
=A4*(B4+$A$2)
This way, all the formulas reference A2 no matter where you copy them, instead
of that reference turning into A3, and A4, and so on.
You can cycle through relative, missed, and absolute references. Press F4 to use
this shortcut.
Turn Calc On/Turn Calc O
The Excel default is to calculate your formulas automatically as they are entered
or when you change the worksheet. In some situations, you may want to set the
calculation to manual. Leaving the setting on automatic is usually not an issue,
but if you are working on a hefty workbook with lots of calculations, you may need
to rethink this one.
360 PART 5 The Part of Tens
Imagine this: You have a cell that innocently does nothing but display the date.
But dozens of calculations throughout the workbook reference that cell. Then
dozens more calculations reference the rst batch of cells that reference the cell
with the data. Get the picture? In a complex workbook, there could be a lot of cal-
culating going on, and the time it takes can be noticeable.
Turning the calculation setting to manual lets you decide when to calculate. Do
this in the Excel Options dialog box; click the File tab on the Ribbon and then click
Options. In the dialog box, click the Formulas tab, in which calculation options are
selected, as shown in Figure18-4. You can select one of the automatic calculation
settings or manual calculation.
Pressing F9 calculates the workbook. Use it when the calculation is set to Manual.
Here are some further options:
What You Press What You Get
F9 Calculates formulas that have changed since the last calculation in the
worksheets.
Shift+F9 Calculates formulas that have changed since the last calculation, just
in the active worksheet.
Ctrl+Alt+F9 Calculates all formulas in all open workbooks, regardless of when
they were last calculated.
Calculate Now This is a button in the Calculation group in the Formulas tab. It calcu-
lates formulas that have changed since the last calculation, in all open
workbooks.
FIGURE18-4:
Setting the
calculation
method.
CHAPTER 18 Ten Tips for Working with Formulas 361
Use Named Areas
Heck, maybe it’s just me, but I think it is easier to remember a word such as Cus-
tomers or Inventory or December than it is to remember B14:E26 or AF220:AR680.
So I create names for the ranges that I know I’ll reference in my formulas and
functions.
Naming areas is easy to do, and in fact, you can do it a few ways. The rst is to use
the New Name dialog box. You can get to this by clicking the Dene Name button
on the Formulas tab of the Ribbon. In the dialog box, you set a range, give it a
name, enter an optional comment, and then click OK (see Figure18-5). The com-
ment feature is useful for further notes about the range. For example, the name of
the range might be “July Sales,” and in the comment area you can enter any fur-
ther related information.
The Name Manager is another dialog box that you can display by clicking its but-
ton on the Formulas tab. This dialog box lets you add, update, and delete named
areas. A really quick way to just add them (but not update or delete) is to follow
these steps:
1. Select an area on the worksheet.
2. Click the Name Box and enter the name.
The Name Box is part of the Formula Bar and sits to the left of where formulas
are entered.
3. Press Enter.
Done! Now you can use the name as you please. Figure18-6 shows a name being
entered in the Name Box. Of course, you can use a particular name only once in a
workbook. After the dened name is entered, you can nd it in the Name Box by
clicking the down arrow in the right of the box.
FIGURE18-5:
Dening a named
area.
362 PART 5 The Part of Tens
Use Formula Auditing
There are precedents and dependents. There are external references. There is
interaction everywhere. How can you track where the formula references are
coming from and going to?
Use the formula auditing tools, that’s how! On the Formulas tab is the Formula
Auditing group. In the section are various buttons that control the visibility of
auditing trace arrows (see Figure18-7).
The Formula Auditing group has several features that let you wade through your
formulas. Besides showing tracing arrows, the group also lets you check errors,
evaluate formulas, check for invalid data, and add comments to worksheets.
FIGURE18-6:
Dening a named
area the
easy way.
FIGURE18-7:
Auditing
formulas.
CHAPTER 18 Ten Tips for Working with Formulas 363
Use Conditional Formatting
Just as the IF function returns a certain value when the rst argument condition
is true and another value when it’s false, conditional formatting lets you apply a
certain format to a cell when a condition is true. On the Home tab in the Styles
section is a drop-down menu with many conditional formatting options.
Figure18-8 shows some values that have been treated with conditional format-
ting. Conditional formatting lets you set the condition and select the format that
is applied when the condition is met. For example, you could specify that the cell
be displayed in bold italic when the value it contains is greater than 100.
Conditions are set as rules. The Rule Types are
»
Format all cells based on their values.
»
Format only cells that contain... .
»
Format only top or bottom ranked values.
»
Format only values that are above or below average.
»
Format only unique or duplicate values.
»
Use a formula to determine which cells to format.
FIGURE18-8:
Applying a format
when a condition
is met.
364 PART 5 The Part of Tens
When the condition is true, formatting can control the following:
»
Borders
»
Number formatting
»
Font settings (style, color, bold, italic, and so on)
»
Fill (a cell’s background color or pattern)
Cells can also be formatted with color schemes or icon images placed in the cell.
Use Data Validation
On the Data tab, in the Data Tools section, is Data Validation. Data Validation lets
you apply a rule to a cell (or a range of cells) that the entry must adhere to. For
example, a cell can be set to accept only an integer entry between 50 and 100 (see
Figure18-9).
When entry does not pass the rule, a message is displayed (see Figure18-10).
The error message can be customized. For example, if someone enters the wrong
number, the displayed error message can say Noodlehead — learn how to count!
Just don’t let the boss see that.
FIGURE18-9:
Setting data
validation.
CHAPTER 18 Ten Tips for Working with Formulas 365
Create Your Own Functions
Despite all the functions provided by Excel, you may need one that you just don’t
see oered. Excel lets you create your own functions by using VBA programming
code; your functions show up in the Insert Function dialog box.
Okay, I know what you’re thinking: Me, write VBA code? No way! It’s true— this
is not for everyone. But nonetheless, here is a short-and-sweet example. If you
can conquer this, you may want to nd out more about programming VBA.Who
knows— maybe one day you’ll be churning out sophisticated functions of your
own! Make sure you are working in a macro-enabled workbook (one of the Excel
le types).
Follow along to create custom functions:
1. Press Alt+F11.
This gets you to the Visual Basic Editor, where VBA is written.
You can also click the Visual Basic button on the Developer tab of the Ribbon.
The Developer tab is visible only if the Developer check box is selected on the
Customize Ribbon tab of the Excel Options dialog box.
Yet another way to get to the Visual Basic Editor is by clicking the Macros
option on the View tab of the Ribbon. Then select the View Macros option. The
Macro dialog box opens.
2. Choose Insert ➪ Module in the editor.
You have an empty code module sitting in front of you. Now it’s time to create
your very own function!
3. Type this programming code, shown in Figure18-11:
Public Function Add(number1 As Double, number2 As Double)
Add = number1 + number2
End Function
FIGURE18-10:
Caught making a
bad entry.
366 PART 5 The Part of Tens
4. Save the function.
Macros and VBA programming can be saved only in a macro-enabled
workbook.
After you type the rst line and press Enter, the last one appears automatically.
This example function adds two numbers, and the word Public lists the
function in the Insert Function dialog box. You may have to nd the Excel
workbook on the Windows taskbar because the Visual Basic Editor runs
as a separate program. Or press Alt+ F11 to toggle back to the Workbook.
5. Return to Excel.
6. Click the Insert Function button on the Formulas tab to display the Insert
Function dialog box (see Figure18-12).
7. Click OK.
The Function Arguments dialog box opens, ready to receive the arguments
(see Figure18-13). Isn’t this incredible? It’s as though you are creating an
extension to Excel, and in essence, you are.
FIGURE18-11:
Writing your own
function.
CHAPTER 18 Ten Tips for Working with Formulas 367
This is a very basic example of what you can do by writing your own function. The
possibilities are endless, but of course, you need to know how to program VBA.
I suggest reading Excel VBA Programming For Dummies, 5th Edition, by Michael
Alexander and John Walkenbach (Wiley).
Macro-enabled workbooks have the le extension .xlsm.
FIGURE18-12:
Finding the
function in the
User Dened
category.
FIGURE18-13:
Using the custom
Add function.
CHAPTER 19 Ten Ways to Get Fancy with Excel 369
Chapter19
Ten Ways to Get Fancy
with Excel
This chapter lists ten cool things Excel can do. Excel is a powerhouse of a
number cruncher and has enough functions to make any other oce pro-
ductivity software seem like a distant cousin. Even with all that power,
there are yet more things Excel can do!
The ten goodies in this chapter show just how helpful Excel can be. Excel can use
data from the Internet, integrate custom lists, deal with duplicates, and make sure
you always see your column headers. There is some serious gold in here!
Calculating Data from Multiple Sheets
Organizing data across multiple sheets is a great feature Excel oers right out of
the box. However, there is a gotcha. What if you need to sum values from more
than one sheet. No problem!
IN THIS CHAPTER
»
Summing across multiple sheets
»
Getting data from the Internet
»
Removing duplicates
»
Freezing headers
»
Determining the correct number
»
Using custom ll lists
»
Getting the nitty-gritty about your
workbook
370 PART 5 The Part of Tens
For example, there could be four sheets of locations— East, West, North, and
South— and one Totals sheet. As long as the data is structured in the same way
on the four location sheets, you can enter this SUM function anywhere on the
Totals sheet. Start your entry with
=SUM(
Then click the needed data cell in the rst location sheet. Hold down Shift and
click the last location sheet’s tab. Then press Enter. The completed formula will
look like this:
=SUM(East:South!C6)
On the totals sheet is now the sum of the data from the four sheets. Neat!
Getting Data from the Internet
There is a world of data out on the Internet, and you may have a need for some
of it.
In the Get & Transform Data options in the Data tab on the Ribbon, click From
Web. A dialog box appears in which you enter the URL of the web page where the
data resides. The web page is returned to Excel. As long as the data on the web
page is structured in a table format, Excel will sense it and oer to populate it on
a worksheet. Figure 19-1 shows how a worksheet is being populated with data
found on the Internet.
Determining the Needed Number
Excel has a really cool feature called Goal Seek. The purpose of Goal Seek is to
determine which number is to be used in a calculation that produces a desired
result of the calculation (that’s a mouthful!).
For example, you may need to know how many $50 units to sell to produce a total
sales amount of $18,000. In the Goal Seek dialog, you point to entries on your
worksheet for the total amount and the price per unit. Goal Seek then returns the
number of needed units. Voilà! Magic!
CHAPTER 19 Ten Ways to Get Fancy with Excel 371
In the What-if Analysis drop-down on the Data tab on the Ribbon, select Goal
Seek. Figure19-2 shows Goal Seek in action.
Removing Duplicates
Imagine this: You have a long list of values going down a column, and you need to
nd duplicates. What can you do? Excel has an easy method to address this. Sim-
ply select all the data and then click the Remove Duplicates button in the Data
Tools section of the Data tab on the Ribbon. The duplicates are removed.
Easy-peasy.
FIGURE19-1:
Retrieving data
from the Internet.
FIGURE19-2:
Determining the
correct number.
372 PART 5 The Part of Tens
You may want to make a copy of your data rst— just in case you need to have
the duplicates after all.
Getting to the Last Row of Your Data
Ugh! Ever have a gazillion rows or columns of data and need a quick way to get to
the last row?
Yeah, I’ve been there, too. There is a fast and fun way to get to the last row: Hover
over the bottom border of the active cell. When the mouse pointer changes to the
crosshairs, double-click. You’re instantly taken to the bottom row of the data.
Doesn’t get any faster than that.
This trick works in any direction. On the active cell, hover over any part of the cell
border to go in that direction— top, bottom, left, or right.
Freezing Panes
When you’re scrolling through a large area of data, the column headings may be
out of the viewing area. This is a problem when you no longer can see what the
data points are! Luckily, Excel has a solution to this problem.
The Freeze Panes feature is used to make the rst column or top row stay xed in
place so it’s always visible. Also, you can apply the freeze to any part of the sheet.
Just select the cell where you want the freeze to start. Freeze Pane is in the Win-
dow section of the View tab on the Ribbon.
Splitting a Worksheet
Split is similar to Freeze Panes, but it has a unique twist: Split literally splits the
worksheet into four areas, each with its own scroll bar. This makes it easy to nav-
igate through data when keeping some of the data in view at all times is helpful.
At rst, Split can be confusing because you can see the same data in more than one
area, depending on how you’re scrolling. But after that initial head scratching is
over, you can see how powerful this feature really is.
CHAPTER 19 Ten Ways to Get Fancy with Excel 373
Filling Cells
A key feature of Excel is the ability to ll cells. This is where you click on the ll
handle (the little box in the lower-right corner of a cell) and drag the mouse in
any direction. If the number or text in the cell belongs to a pattern or list that
Excel knows or can infer, the successive cells ll with the sequence of data. The
most common use of ll is to enter a number in a cell, and then drag— Excel will
ll the successive cells with incremental values.
Besides working with numbers, Excel recognizes days of the week and months of
the year. What if you have another list? No problem! Go to Options in the File tab
of the Ribbon, and select the Advanced tab. Then scroll down to the General sec-
tion and click the Edit Custom Lists button. In the dialog, you can enter custom
lists. Figure19-3 shows how a list of U.S. states is entered. After this is done, you
can enter a state name in a cell and then drag the ll handle to add other states.
Adding Notes to Cells
You can add notes to cells, which is great when you need to provide additional
information about the cell or the value in the cell but you don’t want to put any
text directly on the sheet. Right-click a cell and click New Note in the context
menu. You can edit and delete existing notes as well.
FIGURE19-3:
Entering a
custom ll list.
374 PART 5 The Part of Tens
Getting More Information about a
Workbook or Worksheet
A variety of facts about your workbook are available by clicking the Workbook
Statistics button on the Review tab of the Ribbon. A pop-up appears with infor-
mation about the current sheet and the overall workbook. You can easily see how
many cells on the current worksheet have data, how many formulas are on the
worksheet, and more. At the workbook level, you see the number of worksheets,
tables, formulas, cells with data, and external connections that exist.
CHAPTER 20 Ten Really Cool Functions 375
Chapter20
Ten Really Cool
Functions
The hits just keep on coming! Just when you thought you had all the Excel
functions down pat, here I go rocking the boat. Add this mix of useful func-
tions to your plate of Excel goodies, and you will be that much more of an
Excel master. Be the envy of all the kids on the block!
IN THIS CHAPTER
»
Converting numbers among base
systems
»
Converting values from one unit of
measure to another
»
Finding a common divisor and
common multiple
»
Generating random numbers with a
twist
»
Converting to Roman numerals
»
Getting a fast factorial
»
Finding out the percentage of a year
»
Testing the data type
»
Finding the length
»
Converting the case
376 PART 5 The Part of Tens
Work with Hexadecimal, Octal, Decimal,
and Binary Numbers
In certain lines of work, it is desirable or even necessary to work in another base
system. Designing computer systems is a good example. The computer chips that
run our PCs work with a binary system. Circuits are either on or o. This means
that there are just two possible states— and they are often expressed as 0 and 1.
In base 2, or binary, all numbers are expressed with the digit 0 or 1. The number
20 as we know it in decimal is 10100in binary. The number 99 is 1100011. The
binary system is based on powers of 2.
In other words, in base 10 you count up through ten digits in one position before
moving one position to the left for the next signicant digit. And then the rst
position cycles back to the beginning digit. To make it simple, you count 0 to 9,
add a 1 to the next signicant digit, and start the rst position over at 0. There-
fore, 10 comes after 9.
Binary, octal, and hexadecimal each count up to a dierent digit before incre-
menting the next signicant digit. That’s why when any larger-base number,
such as a base 10 number, is converted to binary, there are more actual digit
places. Look at what happens to the number 20. In base 10, 20 is represented in
2 digits. In binary, 20 is represented in 5 digits.
Octal, based on powers of 8, counts up to 8 digits— 0 through 7. The digits 8 and
9 are never used in octal. Hexadecimal, based on powers of 16, counts up to
16 digits, but how? What is left after 9? The letters of the alphabet, that’s what!
Hexadecimal uses these digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, and F.The
letters A through F represent the decimal values 10 through 15, respectively. If you
have ever worked on the colors for a website, you may know that FFFFFF is all
white. The web server recognizes colors represented in hexadecimal notation and
responds appropriately.
The number 200in decimal notation becomes C8in hexadecimal notation. The
number 99in decimal notation becomes 63in hexadecimal notation.
The point of all this is that there is a group of functions to do all these conversions.
These functions take into account all combinations of conversion among binary,
octal, decimal, and hexadecimal. These functions are shown in the following table.
CHAPTER 20 Ten Really Cool Functions 377
Function What It Does
BIN2DEC Converts binary to decimal
BIN2HEX Converts binary to hexadecimal
BIN2OCT Converts binary to octal
DEC2BIN Converts decimal to binary
DEC2HEX Converts decimal to hexadecimal
DEC2OCT Converts decimal to octal
HEX2BIN Converts hexadecimal to binary
HEX2DEC Converts hexadecimal to decimal
HEX2OCT Converts hexadecimal to octal
OCT2BIN Converts octal to binary
OCT2DEC Converts octal to decimal
OCT2HEX Converts octal to hexadecimal
You can nd these functions in the Engineering section of the Insert Function dia-
log box. Click the Insert Function button on the Formulas tab on the Ribbon.
Convert Units of Measurement
CONVERT is a really great function that Excel provides. Not surprisingly, it con-
verts things. More specically, it converts measurements. The number of mea-
surements it converts is truly impressive. The function converts feet to inches,
meters to feet, Fahrenheit to Celsius, pints to liters, horsepower to watts, and
much more. In fact, more than a dozen categories contain dozens of units of mea-
sure to convert from and to. The major categories follow:
»
Weight and mass
»
Distance
»
Time
»
Pressure
378 PART 5 The Part of Tens
»
Energy
»
Power
»
Temperature
»
Liquid measure
The function takes three arguments: the value, the “from” unit of measure, and
the “to” unit of measure. As an example, here is the function syntax for convert-
ing 10 gallons to liters: =CONVERT(10,"gal","l"). By the way, the answer is 37.85.
Consult the Excel Help system for a full list of available conversions.
Find the Greatest Common Divisor and the
Least Common Multiple
A greatest common divisor is the largest integer that divides evenly into each num-
ber in a set of numbers. In other words, it divides with no remainder. Take the
numbers 5, 10, and 100. The greatest common divisor is 5 because each of the
numbers divided by 5 returns another integer (no decimal portion).
The GCD function takes up to 255 values as its arguments. Non-integer values are
truncated. By its nature, any returned greatest common divisor must equal or be
smaller than the lowest argument value. Often, there is no greatest common divi-
sor other than 1 — which all integers share. The syntax of the GCD function
follows:
GCD(number1,number2,...)
The least common multiple is an integer that is the lowest multiple common
among a group of integers. For example, the least common multiple of 2, 4, and 6
is 12. The least common multiple of 9, 15, and 48 is 720.
The LCM function takes up to 255 values as its arguments. Noninteger values are
truncated. The syntax of the LCM multiple function follows:
LCM(number1,number2,...)
CHAPTER 20 Ten Really Cool Functions 379
Easily Generate a Random Number
The Excel RAND function returns a number between 0 and 1. And that’s it. Usually,
you have to massage the returned number into something useful. The typical
thing to do is multiply it by some number to get it within a range of values, add
the lower limit to that, and nally use INT to turn the whole thing into an integer.
The days of drudgery are over!
The RANDBETWEEN function returns a random integer between two values. Two
arguments are used: the low end of the range and the high end of the range. Just
what you need! For example, =RANDBETWEEN(5,10) returns a whole number
between 5 and 10. Always.
Convert to Roman Numerals
C, V, L, I— I get these mixed up. Is C for 100 or 1,000? What is L for? Whew— I’m
glad I don’t have to memorize these anymore.
The ROMAN function takes care of it all. Just throw a number in the normal format
you are familiar with, and out comes the equivalent Roman numeral. Easy! The
syntax is
=ROMAN(number to convert,optional style)
Factor in a Factorial
If you like multiplication, you will love the FACT function. A factorial, simply put,
is the product of multiplying sequential integers. In math notation, 6! (notice the
exclamation point) is 1 × 2 × 3 × 4 × 5 × 6, which equals 720. Try it on your calcu-
lator, or use an Excel sheet, of course.
The FACT function makes the tedious entry go away, which I think you will like.
FACT just takes a number— the number of integers to use for the grand product.
380 PART 5 The Part of Tens
Determine Part of a Year with YEARFRAC
If you need to know what percentage of a year a range of dates is, Excel has the
perfect function for you! YEARFRAC returns a percentage of a year. You feed the
function a start and end date, and an optional basis for how to count dates (such
as a 360-day year, a 365-day year, and so on). The number given back from the
function is a percentage— a number less than 1, assuming that the range of dates
is less than a full year. An exact one-year range returns 1, and a range longer than
a year returns a number larger than 1.
Find the Data TYPE
The content in a cell may be text, a number, a logical value, an error, or an array.
The TYPE function tells you which type the content is. When you’re looking at a
cell, it’s obvious what the type is. However, if your formulas are using cell refer-
ences, you may wish to put the TYPE function into the formula before attempting
a mathematical operation. This ensures that you can have a valid result returned
instead of an error. For example, A4 has 25 and A5 has “Apple.” An attempt to add
these results in an error. Instead put the TYPE function into the formula to deter-
mine if the calculation should take place. The formula would look like this:
=IF(TYPE(A4)=1&TYPE(A5)=1,A4+A5,"Unable to calculate")
The result in this case is Unable to calculate because you cannot add a number
with text.
The TYPE function returns ve possible values:
Value What It Means
1Number
2Text
4A logical value (And, Or, and so on)
16 An error
64 An array
CHAPTER 20 Ten Really Cool Functions 381
Find the LENgth of Your Text
Finding the length of a text string can be very useful in cases where you have
many pieces of similar text. For example, if you have a long list of factory part
codes, you can test if any are invalid by testing the length. Let’s say the valid for-
mat for a factory code is ve characters. Running the LEN function in a column
next to the factory codes can reveal those that have a length that is not ve char-
acters and are therefore invalid.
The LEN function is simple; it just takes one argument— the cell or actual text
being referenced. For example, here is the LEN function referencing cell F15:
=LEN(F15)
Just in CASE
Three helpful functions make formatting your text a breeze. These CASE functions
take a text string and return as all lowercase, all uppercase, or in proper case (each
word starts with an uppercase letter). This is useful when formatting titles and
headings.
Assuming Hello, how are you? is in cell A5:
»
LOWER(A5) returns hello, how are you?
»
UPPER(A5) returns HELLO, HOW ARE YOU?
»
PROPER(A5) returns Hello, How Are You?
