Problem.xlsx

Problem

The US Department of Energy’s Fuel Economy Guide provides fuel efficiency data for cars and trucks. A portion of the data for 35 standard pickup trucks produced by Chevrolet and General Motors is listed below (scroll down). The column labeled Drive identifies whether the vehicle has two-wheel drive (2WD) or four-wheel drive (4WD). The column labeled Displacement shows the engine’s displacement in liters indicating its size and power, the column labeled Cylinders specifies the number of cylinders the engine has, and the column labeled Transmission shows whether the truck has automatic transmission or a manual transmission. The column labeled City mpg shows the fuel efficiency rating for the truck for city driving in terms of miles per gallon (mpg).

part a)Develop an estimated regression equation that can be used to predict the fuel efficiency given the engine’s displacement and whether the truck is 2WD or 4WD. Clearly define your variables.

Answer to part a)

part b) Comment on the significance of the model and the variables, for the model developed in part (a).

Answer to part b)

part c)Provide an interpretation for the coefficient of each independent variable in the model developed in part (a).

Answer to part c)

part d)Predict the fuel efficiency for a 4WD truck with an engine displacement of 5.1 liters.

Answer to part d)

part e)Starting with the variables Drives, Displacement, Cylinders and Transmission, write down the estimated regression equation for the best model that you could build using the Backward Elimination algorithm. Comment on how good you think this model is.

Answer to part e)

Name Drive Displacement Cylinders Transmission CityMPG

C1500 SILVERADO 2WD 4.3 6 Auto 15

C1500 SILVERADO 2WD 4.3 6 Manual 15

C1500 SILVERADO 2WD 4.8 8 Auto 15

C1500 SILVERADO 2WD 4.8 8 Manual 16

C1500 SILVERADO 2WD 5.3 8 Auto 11

C1500 SILVERADO 2WD 5.3 8 Auto 15

C1500 SILVERADO 2WD 5.3 8 Auto 15

SSR PICKUP 2WD 5.3 8 Auto 15

CHEVY C2500 SILVERADO 2WD 6 8 Auto 10

CHEVY C2500 SILVERADO 2WD 6 8 Auto 10

C1500 SIERRA 2WD 4.3 6 Auto 16

C1500 SIERRA 2WD 4.3 6 Manual 15

C1500 SIERRA 2WD 4.8 8 Auto 15

C1500 SIERRA 2WD 4.8 8 Manual 16

C1500 SIERRA 2WD 5.3 8 Auto 11

C1500 SIERRA 2WD 5.3 8 Auto 15

C1500 SIERRA 2WD 5.3 8 Auto 15

K1500 SILVERADO 4WD 4.3 6 Auto 14

K1500 SILVERADO 4WD 4.3 6 Manual 14

K1500 SILVERADO 4WD 4.8 8 Auto 14

K1500 SILVERADO 4WD 4.8 8 Manual 14

K1500 SILVERADO 4WD 5.3 8 Auto 10

K1500 SILVERADO 4WD 5.3 8 Auto 13

K1500 SILVERADO 4WD 5.3 8 Auto 14

S10 PICKUP 4WD 4.3 6 Auto 15

S10 PICKUP 4WD 4.3 6 Manual 14

K1500 SIERRA 4WD 4.3 6 Auto 15

K1500 SIERRA 4WD 4.3 6 Manual 14

K1500 SIERRA 4WD 4.8 8 Auto 14

K1500 SIERRA 4WD 4.8 8 Manual 14

K1500 SIERRA 4WD 5.3 8 Auto 10

K1500 SIERRA 4WD 5.3 8 Auto 13

K1500 SIERRA 4WD 5.3 8 Auto 14

SONOMA 4WD 4.3 6 Auto 15

SONOMA 4WD 4.3 6 Manual 14