=+d. From the output, it appears that lubrication regimen may not be providing useful information.

A regression with the corresponding predictors removed resulted in SSResid 5 48.426. What is the coefficient of multiple determination for this model, and what would you conclude about the importance of the lubrication regimen?

e. A model with predictors for BHP, supplier, and lubrication regimen, as well as predictors for interactions between BHP and both supplier and lubrication regiment, resulted in SSResid 5