8.2.9. Agronomists have identied 7 different geographical areas with respect to raising corn in West Virginia and have managed to obtain an experimental farm in each area. To see if a single variety of corn can be recommended for the entire state, the two leading varieties are compared for yield at all '? localities. The following yields in bushels per acre are obtained: Geographical Area Variety 1 2 3 4 5 6 7 A 45 41 5s 60 42 32 57 B 47 44 62 63 46 35 59 (B A) 2 3 4 3 4 3 2 (1-14).2 4 9 16 9 16 9 4 Why is it a good design to compare the two varieties at each location? What is the average difference in the yields? Show that the estimated standard error of this difference is 0.309. The seed company that sells variety B claims it will exceed variety A in yield by more than 2 bushels per acre. Test this claim at o: = 0.05. F"??? I'D . What is your conclusion about the seed company's claim? f. Find a 95% central condence interval on the mean difference in yield of the two types of seed. How is this condence interval related to the test in part (1