SCENARIO 14-14
An automotive engineer would like to be able to predict automobile mileages.She believes that the
two most important characteristics that affect mileage are horsepower and the number of cylinders (4
or 6)of a car.She believes that the appropriate model is
Y = 40 - 0.05X1 + 20X2 - 0.1X1X2
where X1 = horsepower
X2 = 1 if 4 cylinders, 0 if 6 cylinders
Y = mileage.
-Referring to Scenario 14-14, the fitted model for predicting mileages for 6-cylinder cars is
________.
A) 40 - 0.05X1
B) 40 - 0.10X1
C) 60 - 0.10X1
D) 60 - 0.15X1

Question

Quizplus · Accepted Answer

For 6-cylinder cars, X2 = 0. Substituting X2 = 0 into the model Y = 40 - 0.05X1 + 20X2 - 0.1X1X2 gives Y = 40 - 0.05X1.

SCENARIO 14-14 An Automotive Engineer Would Like to Be Able to Predict