step  To run a linear regression analysis, from the menus choose:

Analyze
  Regression
   Linear...

step  Select time as the dependent variable.

step  Select diam as the independent variable.

step  Select type as the case labeling variable.

step  Click Plots.

step  Select *SDRESID as the y variable and *ZPRED as the x variable.

step  Select Histogram and Normal probability plot.

step  Click Continue.

step  Click Save in the Linear Regression dialog box.

step  Select Standardized in the Predicted Values group.

step  Select Cook's and Leverage values in the Distances group.

step  Click Continue.

step  Click OK in the Linear Regression dialog box.

These selections produce a linear regression model for polishing time based on diameter. Diagnostic plots of the Studentized residuals by the model-predicted values are requested, and various values are saved for further diagnostic testing.