Suppose that a response variable y is related to four predictor variables, 1 x , 2 x , 3 x , and 4 x , so that k54.

1. Enter the observed values of y and each of the k54 predictor variables into the first

(k11) columns of a MINITAB worksheet. Once this is done, the main inferential tools for multiple regression analysis are generated using Stat ➤ Regression ➤ Regression

➤ Fit Regression Model. The Dialog box for the Regression command is shown in Figure 13.23(a).

2. Select y for the “Responses” box and x1, x2, . . . , xk for the “Continuous predictors” box.

You may now choose to generate some residual plots to check the validity of your regression assumptions before you use the model for estimation or prediction. Choose Graphs to display the Dialog box for residual plots, and choose the appropriate diagnostic plot.