Refer to the hops data in Exercise 13.17. Obtain the residuals from each of the four models you selected in Exercise 13.17.
a. Is there evidence in the residuals of a violation of the normality condition?
b. Is there evidence in the residual plots of a violation of the constant variance ­condition?
c. Perform a BP test for constant variance. Does the test agree with your observations in part (a)?
d. Determine the appropriate Box€“ Cox transformation for these data.
In exercise

Variety of Hops Fuggle Northerm Brewer Hallertau Field P S Field P S Field P S Field P T 12.1 16.8 4 55 6.5 4.4 68 16.7 4.4 2 5.8 174 58 2107170 622 5.3 171 58 24.9185 7.5 3 10.6 17.9 5.9 3 4.7 18.4 7.0 3 4.7 18.1 7.8 4 5.5 18.9 62410218.07.74 4.6 174 58 44.171 5.7 4.1 18.7 7.1 6 9. 21.3 6 64418.6 7.5 6 3.9 179 5.9 7 88 18.5 7.2 7 4.019.3 677 3.8 19.1 7.1 3.5 214 5.9 9 8 19.9 8.5 93221.4 6. 9 3.4 19.0 76 80 19.1 6.6 10 3.3 20.6 87 10 3.1 17.7 71 7.6 21.1 7.3 1 3.0 19.8 85 3.0 20.9 7.8 12 3.7 17.3 6.9124174 6.9 12 2.9 21.2 79 1 2.7 19.0 8.8 13 3.2 185 8613 5.8 19.2 8413 2.8 17.3 6.9 13 2.5 20 8.5 1 7.2 16.7 44 3 5.7 171 5.9 1 2 5 5.2 17.7 6.6 6 5.1 184 6.9 7 4.8 168 69 8 4.8 18.2 62 9 4.8 20.7 84 10 4.7 21.3 6210 11 4.3 21.2 7411 9.6 18.0 6.9 5 45 18.3 7.5 5 88 19.1 6,5 8 38 19.2 65 8 0