As a finance major, you are curious about the dynamics of investing in residential real estate in smaller economies. You decide to focus your study on Tehran, Iran. You collect data on actual sales prices and some other major project variables of single-family residential apartments in the country and store it in the file ResidentialBuilding .

a. Using all the data as the training sample, develop a regression tree model to predict actual sales price.

b. What conclusions can you reach about the actual sales price?

c. Using half the data as the training sample and the other half of the data as the validation sample, develop a regression tree model to predict actual sales price.

d. What differences exist in the results of (a) and (c)?