||a. Which of the explanatory variables in the regression are statistically significant? Explain. How much of the total variation in pie sales does the regression model explain? b. Compute the price elasticity of demand for pies at the firm??s mean price ($7.50) and mean weekly sales quantity (20,000 pies). Next, compute the cross-price elasticity of demand. Comment on these estimates. c. Other things equal, how much do we expect sales to grow (or fall) over the next year? d. How accurate is the regression equation in predicting sales next quarter? Two years from now? Why might these answers differ? e. How confident are you about applying these test-market results to decisions concerning national pricing strategies forpies?