The sales manager of a large automotive parts distributor wants to estimate the total annual sales for each of the company's regions. Five factors appear to be related to regional sales: the number of retail outlets in the region, the number of automobiles in the region registered as of April 1, the total personal income recorded in the rst quarter of the year, the average age of the automobiles (years), and the number of sales supervisors in the region. The data for each region were gathered for last year. For example, see the following table. In region 1 there were 1,739 retail outlets stocking the company's automotive parts, there were 9,270,000 registered automobiles in the region as of April 1, and so on. The region's sales for that year were $37,702,000. Number of Number of Personal Annual Sales Retail Automobiles Income ($ Average Age of Number of ($ millions), Outlets, Registered billions), Automobiles Supervisors, y X1 (millions), X2 X3 (years), X4 X5 37.702 1,739 9.27 85.4 3.5 9.0 24.196 1,221 5.86 60.7 5.0 5.0 32.055 1,846 8.81 68.1 4.4 7.0 3.611 120 3.81 20.2 4.0 5.0 17.625 1,096 10.31 33.8 3.5 7.0 45.919 2,290 11.62 95.1 4.1 13.0 29.600 1.687 8.96 69.3 4.1 15.0 8.114 241 6.28 16.3 5.9 11.0 20.116 649 7.77 34.9 5.5 16.0 12.994 1,427 10.92 15.1 4.1 10.0 b. The following regression equation was obtained using the five independent variables. What percent of the variation is explained by the regression equation? (Round your answer to 4 decimal places.) The regression equation is Sales = 19.7 0.00063 outlets +1.74 automobiles + 0.410 income + 2.04 age 0.034 bosses SE Predictor Coefficient Coefficient t p Constant 19.672 5.422 3.63 0.022 Outlets 0.000629 0.002638 0.24 0.823 Automobiles 1.7399 0.5530 3.15 0.035 Income 0.40994 0.04385 9.35 0.001 Age 2.0357 0.8779 2.32 0.081 Bosses 0.0344 0.1880 0.18 0.864 Analysis of Variance Source DF 55 MS F p Regression 5 1,593.81 318.76 140.36 0.0001 Residual Error 4 9.08 2.27 Total 9 1602.89 -:| c. Conduct a global test of hypothesis to determine whether any of the regression coefficients are not zero. Use the 0.05 significance level. (Round your answer to 2 decimal places.) 6 Answer is not complete. d. Conduct a test of hypothesis on each of the independent variables. Would you consider eliminating "outlets" and "bosses"? Use the 0.05 significance level. (Negative amounts should be indicated by a minus sign. Round your answers to 3 decimal places.) x Answer is not complete. Delete "outlets" and "bosses". Critical values and aree. The regression has been rerun below with \"outlets" and "bosses" eliminated. Compute the coefficient of determination. How much R2 has changed from the previous analysis? (Round your answer to 4 decimal places.) The regression equation is Sales = 18.9 +1.61 automobiles + 0.400 income +1.96 age SE Predictor Coefficient Coefficient t p Constant 18.924 3.636 5.20 0.002 Automobiles 1. 6129 0. 1979 8. 15 0. 000 Income 0.40031 0.01569 25.52 0.000 Age 1.9637 0.5846 3.36 0.015 Analysis of Variance Source DF 55 MS F p Regression 3 1,593.66 531.22 345.25 0.000 Residual Error 6 9.23 1.54 Total 9 1,602.89