Statistical Analysis with Excel For Dummies. Joseph Schmuller

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СКАЧАТЬ Completing the Function Arguments dialog box for SUMIF.

The formula in the Formula bar is easier to understand than

       = SUMIF(B2:B13,"North", C2:C13)

      isn’t it?

      Incidentally, the same cell range can be both the Range and the Sum:range. For example, to sum just the cells for which Revenue_Millions is less than 25, you’d use

       =SUMIF(Revenue_Millions, "< 25", Revenue_Millions)

      

The second argument (Criteria) is always in double quotes.

      What about SUMIFS? That one is useful if you want to find the sum of revenues for North but only for the years 2006 and 2007. Follow these steps to use SUMIFS to find this sum:

      1 Select a cell for the formula result.The selected cell is C17.

      2 Choose Formulas | Math & Trig.

      3 From the pop-up menu that appears, choose SUMIFS.This step opens the Function Arguments dialog box.

      4 In the Function Arguments dialog box, enter the appropriate values for the arguments, as shown in Figure 2-21.Notice that, in SUMIFS, the Sum Range argument appears first. In SUMIF, however, it appears last.Note that the formula in the Formula bar is now=SUMIFS(Revenue_Millions,Year,"<2008",Region,"North")FIGURE 2-21: The completed Function Arguments dialog box for SUMIFS.

      5 Click OK.The answer, 46, appears in the selected cell.

      With unnamed arrays, the formula would have been

       =SUMIFS(C2:C13,A2:A13,"<2008",B2:B13,"North")

      which seems much harder to comprehend.

      

A defined name involves absolute referencing. (See Chapter 1.) Therefore, if you try to autofill from a named array, you'll be in for an unpleasant surprise: Rather than autofill a group of cells, you copy a value over and over again.

      Here’s what I mean. Suppose you assign the name Series_1 to A2:A11 and Series_2 to B2:B11. In A12, you calculate SUM(Series_1). Because you’re clever, you figure you’ll just drag the result from A12 to B12 to calculate SUM(Series_2). What do you find in B12? SUM(Series_1) — that's what.

      

Excel does not treat array names as case-sensitive. If the named array is Test, for example, SUM(Test), SUM(test), and SUM(tEST) all give you the same result.

      

You can't name an array in Excel on the iPad. If you name an array in a Windows or Mac Excel spreadsheet, however, and your Microsoft 365 account includes the iPad, you can open that spreadsheet on the iPad and the named array works just fine.

Creating Your Own Array Formulas

      In addition to Excel’s built-in array formulas, you can create your own. (Again, not on the iPad.) To help things along, you can incorporate named arrays.

Figure 2-22 shows two named arrays, X and Y, in columns C and D, respectively. X refers to C2 through C5 (not C1 through C5), and Y refers to D2 through D5 (not D1 through D5). XY is the column header for column F. Each cell in column F stores the product of the corresponding cell in column C and the corresponding cell in column D.

      FIGURE 2-22: Two named arrays and an array formula.

      An easy way to enter the products, of course, is to set F2 equal to C2*D2 and then autofill the remaining applicable cells in column F.

      Just to illustrate array formulas, though, follow these steps to work on the data in the worksheet (refer to Figure 2-22):

      1 Select the cell to start the output array.That would be F2. (Figure 2-21 shows the selected cell.)

      2 Into the selected cell, type the formula.The formula here is =X * Y

      3 Press Enter.The answers appear in F2 through F5, as Figure 2-23 shows.

      FIGURE 2-23: The results of the array formula =X * Y.

When you name a range of cells, make sure that the named range does not include the cell with the name in it. If it does, an array formula like {=X * Y} tries to multiply the letter X by the letter Y to produce the first value, which is impossible and results in the exceptionally ugly #VALUE! error.

      Using data analysis tools

      Excel has a set of sophisticated tools for data analysis. They reside in the Analysis ToolPak. This ToolPak isn't available for the iPad, but a similar package, the XLMiner Analysis ToolPak, is. I mention it in the next section.

Table 2-1 lists the ToolPak tools I cover. (The one I don’t cover, Fourier Analysis, is extremely technical.) Some of the terms in the table may be unfamiliar to you, so I define them throughout this book.

TABLE 2-1 Excel's Data Analysis Tools

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Tool	What It Does
Anova: Single Factor	Performs analysis of variance for two or more samples.
Anova: Two-Factor with Replication	Performs analysis of variance with two independent variables, and multiple observations in each combination of the levels of the variables.
Anova: Two-Factor without Replication	Performs analysis of variance with two independent variables, and one observation in each combination of the levels of the variables; It’s also a repeated measures analysis of variance.
Correlation	With more than two measurements on a sample of individuals, calculates a matrix of correlation coefficients for all possible pairs of the measurements.