Which of the following are regression results where Car Price is the dependent variable:

Regression Statistics

R2=0.446

Adjusted

R2=0.441

Observations = 804

Independent Variables Coefficients Standard Error t Stat P-value

Intercept 6758.76 1876.967 3.601 0.000

Mileage -0.17 0.032 -5.326 0.000

Cylinder 3792.38 683.180 5.551 0.000

Liter -787.22 867.062 -0.908 0.364

Doors -1542.75 320.456 -4.814 0.000

Cruise 6289.00 657.992 9.558 0.000

Sound -1993.80 571.776 -3.487 0.001

Leather 3349.36 597.681 5.604 0.000

Car Price is measured in dollars. The independent variables are:

• Mileage: number of miles the car has been driven
• Cylinder: number of cylinders in the engine
• Liter: a more specific measure of engine size
• Doors: number of doors
• Cruise: dummy variable representing whether the car has cruise control (1 = cruise, 0 = no cruise)
• Sound: dummy variable representing whether the car has upgraded speakers (1 = upgraded, 0 = standard)
• Leather: dummy variable representing whether the car has leather seats (1 = leather, 0 = cloth)

What is true about the estimated coefficients?

Select one:

a. The "Mileage" coefficient is unexpectedly small compared to the others, suggesting that miles driven is unimportant in the selling price of a used car.

b. The "Sound" coefficient is unexpectedly negative, suggesting that cars with upgraded speakers are associated with a lower selling price.

c. The "Mileage" coefficient is unexpectedly negative, since higher miles driven should be associated with a higher selling price.

d. The negative "Door" coefficient indicates that more doors on a car reduce the car's mileage.