step  To check Cook's distance by the centered leverage value, recall the Simple Scatterplot dialog box.

step  Deselect Standardized Residual as the y variable and select Cook's Distance as the y variable.

step  Deselect Zscore: Wheelbase as the x variable and select Centered Leverage Value as the x variable.

step  Click OK.

The resulting scatterplot shows several unusual points.

step  To identify the points, activate the graph by double-clicking on it.

step  Click the Point Identification tool.

step  Select the points.

The point with the largest Cook's distance is the 3000GT. It does not have a high leverage value, so while it adds a lot of variability to your regression estimates, the 3000GT did not affect the slope of the regression equation. Similarly, many of the cases with high leverage values do not have large Cook's distances, so they are not likely to have exerted undue influence on the model. The most worrisome case is the SL-Class, which has both a high leverage and a large Cook's distance. This vehicle has a large wheelbase and price tag, so its influence is related to the problems you observed in the residual scatterplots.