Below is the output for the estimated regression equations u

Below is the output for the estimated regression equations using all possible variables as predictor variables for CMPG. The predictor variables used are Sedan, TruckSUV, Engine, Cyl, HP, Weight, Length, and Height.

a.Write out the estimated linear regression equation using the given computer output. (4 points)

b.Do the estimated coefficients for the predictor variables make sense? Why or why not?

c.If we were to use only variables that are significant at a=0.5, which variables would we use for predicting city gas mileage? Do you feel like there are any variables that should be significant but are not? Explain.

d.Give the point prediction for the city gas mileage of a vehicle that is a sedan, has a 2 liter engine with 4 cylinders and 112 horsepower, weighs 2500 pounds, is 175 inches long and 67 inches wide. (4 points)

e.Give the 95% prediction interval for the car described in (d). The distance value is d=0.057 and t0.025,378. Note that s is referred to in the output as Residual standard error.

Model 1

Solution