Microsoft Office Tutorials and References

In Depth Information

**Using the Analysis Toolpak data analysis tools**

Note

The LINEST and LOGEST functions return only the y-axis coordinates used for

calculating lines and curves. The difference between them is that LINEST projects a straight line

and LOGEST projects an exponential curve. You must be careful to match the

appropriate function to the analysis at hand. The LINEST function might be more appropriate

for sales projections, and the LOGEST function might be more suited to applications

such as statistical analyses or population trends.

The GROWTH function

Where the LOGEST function returns a mathematical description of the exponential

regression curve that best its a set of known data, the GROWTH function finds points that lie

along that curve. The GROWTH function works like its linear counterpart, TREND, and takes

the form =GROWTH(
known_y’s, known_x’s, new_x’s, const
). For more information about the

GROWTH function’s arguments, see “The TREND function” earlier in this chapter.

Using the Analysis Toolpak data analysis tools

The Analysis Toolpak add-in is part of the deal when you purchase Excel, although you

might not know it.
Add-ins
are little packages of tools that more or less seamlessly integrate

into the user interface of Excel. However, they require you to install them first. The

following sections discuss the installation of—and the tools included with—the Analysis Toolpak.

Installing the Analysis Toolpak

To see whether you have the Analysis Toolpak installed, click the Data tab on the ribbon. If

the Data Analysis button is there, you’re good to go. If not, click the File tab, click Options,

and select the Add-Ins category. Click the Go button at the bottom of the dialog box to

display the Add-Ins dialog box. In the Add-Ins dialog box, select the Analysis Toolpak check

box, and then click OK to install it. You can also select the Analysis Toolpak—VBA check box

if you want the Toolpak functions to be available for programmatic usage, but this add-in is

not necessary for our purposes.

When you click the Data Analysis button on the Data tab, the Data Analysis dialog box

appears, as shown in Figure 17-6.