A national homebuilder builds single-family homes and condominium-style townhouses. The Excel file House Sales provides information on the selling price, low cost, type of home, and region of the country (where 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) Develop an interaction term to model the effect one variable dependent on another variable. An interaction term is defined by X3 = X1 * X2. In this case, try an interaction term with Townhouse*Lot cost. Add the interaction term to your existing model and check p-values. Drop the unnecessary variables. C) Using the final model, find out the predicted price for either a single-family home or a townhouse with a lot cost of $30,000