In Problem 13.6 on page 470, you used the total worldwide revenue ($ millions) and full time voluntary turnover (%) data stored in BestCompanies to predict number of full time jobs added. Develop a regression model to predict the number of fulltime jobs added that includes full time voluntary turnover, total worldwide revenue, and the interaction of full time voluntary turnover and total worldwide revenue.
a. At the 0.05 level of significance, is there evidence that the interaction term makes a significant contribution to the model?
b. Which regression model is more appropriate, the one used in this problem or the one used in Problem 13.6? Explain.