13.41 U.S. and foreign used cars Refer to the used car data file from Exercise 13.11. The prediction equation relating y = selling price of used car (in $) as a function of x1 = age of car and x2 = type of car 11 = US, 0 = Foreign2 is yn = 20,493 - 1,185x1 - 2,379x2.

a. Using this equation, find the prediction equation relating selling price and age, separately for U.S. and foreign cars.

b. Predict by how much the price changes for a one year increase in the age of the car. Does this apply for both types of cars? Explain.

c. Find the predicted price of a (i) U.S. and (ii) foreign car that is eight years old. Show how the difference between them relates to a parameter estimate for the model.