Continuing Problem 6 with the data in the file P10_18.xlsx, refer to the original multiple regression model as the reduced equation. Suppose now that the antique collector believes that the rate of increase of the auction price with the age of the item will be driven upward by a large number of bidders.
a. Revise the reduced regression equation to model this additional feature of the problem. Estimate this larger regression equation, called the complete equation.
b. Using a 5% significance level, perform a partial F test to check whether the complete equation is significantly better than the reduced equation. Briefly explain your findings.