Dirt bikes, part 2.

The model in Exercise 30 is missing one predictor that we might have expected to see. Engine Displacement is highly correlated (r 0.783) with MSRP, but that variable has not entered the model (and, indeed, would have a P-value of 0.54 if it were added to the model).

Here is some evidence to explain why that may be. (Hint:

Notice that Displacement is the response variable in this regression.)

Dependent variable is: Displacement R-squared 95.9% R-squared (adjusted) 95.7%

s = 35.54 with 100 - 6 = 94 degrees of freedom

a) What term describes the reason Displacement doesn’t contribute to the regression model for MSRP?

b) Find the value of the Variance Inflation Factor for Displacement in the regression on MSRP.

Transcribed Image Text:

Variable Intercept Bore Clearance Engine Stroke Total Weight Wheelbase Coeff SE(Coeff) t-ratio P-value -8.05901 48.42 -0.166 0.8682 9.10890 0.3601 25.3 0.0001 3.55912 3.048 1.17 0.2460 -27.3943 5.264 -5.20 0.0001 1.03749 0.1768 5.87 0.0001 -10.0612 2.008 -5.01 0.0001