An automotive engineer would like to be able to predict automobile mileages. She
ID: 3124996 • Letter: A
Question
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.
The fitted model for predicting mileages for 4-cylinder cars is ________.
A. 40 - 0.05X1
B. 60 - 0.10X1
C. 60 - 0.15X1
D. 40 - 0.10X1
The fitted model for predicting mileages for 6-cylinder cars is ________.
A. 40 - 0.10X1
B. 60 - 0.15X1
C. 40 - 0.05X1
D. 60 - 0.10X1
A. 40 - 0.05X1
B. 60 - 0.10X1
C. 60 - 0.15X1
D. 40 - 0.10X1
Explanation / Answer
The fitted model for predicting mileages for 4-cylinder cars is:
As X2 = 1 for 4 cylinders
Y = 40 - 0.05X1 + 20*1 - 0.1X1*1
or, Y = 50 - 0.15*X1
Answer: C. 60 - 0.15X1
The fitted model for predicting mileages for 6-cylinder cars is:
As X2 = 0 for 6 cylinders
Y = 40 - 0.05X1 + 20*0 - 0.1X1*0
or, Y = 40 - 0.05*X1
Answer: C. 40 - 0.05X1