The Undergraduate Data sheet of the file P10_21.xlsx contains information on 101 undergraduate business programs in the U.S., including various rankings by Business Week. Use forward, backward, and stepwise regression analysis to explore the relationship between the median starting salary and the following set of potential explanatory variables: annual cost, full-time enrollment, faculty-student ratio, average SAT score, and average ACT score. Do these three methods all lead to the same regression equation? If not, do you think any of the final equations are substantially better than any of the others?