Data Analysis with Microsoft Excel: Updated for Office 2007

Chapter 9 Multiple Regression 379

To create a normal probability plot of the residuals:

1 Click the Male Faculty Regression sheet tab.

2 Click Single Variable Charts from the StatPlus menu and then click

Normal P-plots.

3 Click the Data Values button, click the Use Range References option

button, and select the range C27:C71. Click OK.

4 Click the Output button and specify the new chart sheet Male

Residual P-plot as the output destination. Click OK.

5 Click OK to start generating the plot. See Figure 9-16.

Figure 9-16
Normal
P-plot
of residuals
for the male

faculty data

The plot is reasonably straight, although there is a point at the upper

right that is a little farther to the right than expected. This point belongs to

the employee whose salary is $8,000 more than predicted, but it does not

appear to be too extreme. You can conclude that the residuals seem consis-

tent with the normality assumption.