A national homebuilder builds single‐family homes and condominium‐style townhouses. The Excel file House Sales provides information on the selling price, lot cost, type of home, and region of the country (M = Midwest, S = South) for closings during one month.
a. Develop a multiple regression model for sales price as a function of lot cost and type of home.
b. Determine if any interactions exist between lot cost and type of home, and find the best model.
c. Develop a regression model for selling price as a function of lot cost and region. (Note that the categorical variable region has more than two levels.)