25)

Mpg: Home Runs and Lively Baseballs Has the number of home runs hit by major league teams been changing over time? For the 41 years from 1960 to 2000, the average number of home runs hit per game per team for each season was computed in order to assess any change over time. Initially, simple linear regression was used to study the trend in home runs hit over the period 1960 to 2000 by using year to predict the average number of home runs per game per team in that year. However, it was pointed out that after the 1976 season the manufacturer of major league baseballs was changed from Spaulding to Rawlings. Because the change in the baseball used might affect the number of home runs (for example, if Rawlings produces a livelier ball, this will likely lead to more home runs), it was decided to include an additional variable, namely, 0 if before 1976 (that is, the Spauldlng baseball was used). mantlfaCturer : { 1 if after 1976 (that is, the Rau'lings basedball was used). A multiple regression analysis was performed using the model: \"Avg. home runs per game per team = Bo + 131(Year) + 52(Manufacturer) Anah'sis of Variance Source d_f Sum of SMES MOM _ 2 0 744384 (Regressxon) END! 38 2 53933 Parameter Estimates Variable d_f Patametet Estimate Standard Error Intercept 1 -2' 91180 12 8900 Year 1 0 01498 0 00650 Manufacturer 1 -0 1032 0 1153 Using the regression equation, what is the predicted average number of home runs per game per team in 1997? O 1.506 O 1.889 O 1.934 0 29.624 Question 28 Below is the output from predicting the taste of cheese (a score based on a sample of 30 cheese experts) using the concentration of acetic acid (Acetic), hydrogen sulfide (H2S) and lactic acid (Lactic) in each cheese. Table 3 Regression Statistics Multiple R 0.802872775 R Square 0.644604692 Adjusted R Square 0.603597541 Standard Error 10 23447035 Observations ANOVA df SS MS Significance F Regression 4939.532702 1646.510901 15.71932403 4.94E-06 Residual 2723 353964 104.7443832 Total 7662 886667 Coefficients Standard Error : Stat P.value Lower 95% Upper 95% Intercept -9.27303817 21.56638814 -0.42997641 6.718-01 -53.603 35.057 Acetic 0.064082653 4.58119814 0.013988186 9.89E-01 -9.353 9.48 H2S 4. 129493845 1.231983624 3.351906441 2.47E-03 1.597 6.662 Lactic 25.92855139 12. 13276165 2.137069213 0.042167705 0.989 50.868 What is the regression equation (round coefficients to two decimals)? O Taste = 3598.71 -292.84*Acetic -43.16*H2S + 25.93*Lactic O Taste = 0.06 + -9.27*Acetic + 4.13*H2S + 25.93*Lactic O Taste = -9.27 + 0.06*Acetic + 4.13*H2S + 25.93*Lactic O Taste = -9.27 + 4.58*Acetic + 1.23*H2S + 12.13*Lactic