A) B) C) 18. Has the number of home runs hit by Major League teams been changing over time? For 51 years, from 1960 to 2010, the average number of home runs hit per game per team for each season was computed, to assess any change over time. Initially, to study the trend in home runs over this period, simple linear regression was performed by using year to predict the average number of home runs per game per team in that year. However, it was pointed out that the manufacturer of Major League baseballs was changed from Spalding to Rawlings after the 1976 season. Because the change in the type of baseball used might have affected the number of home runs (for example, the production of a livelier ball by Rawlings would likely lead to more home runs), it was decided to include an additional variable: '0. 1f before 19"6 (that 15. the Spalding baseball was used] Manufacturer 2 '. I_I, If after 19 {6 (that IS; the Rawlings baseball \"as Used} A multiple regression analysis was performed using the model ,u = average home runs per game per team 50 + .6,(year) + 52(manufacturer). The following results were obtained. Analysis of Variance Source df Sum of squares Model 2 0.744384 Error 48 2.53933 Parameter Estimates Variable df Parameter estimate Standard error Intercept 1 -27.9118 12.89 Year 1 0.014977 0.0065 Manufacturer 1 -0.107816 0.11573 Suppose we wish to test the hypotheses H0: 5, = g = 0 and Ha: at least one of the is not zero. Using the ANOVA F test, the value of the F statistic is: 0.06. 0.29. 5.34