For Exercises 31 and 32, use the indicated output to perform Tukey's test, using the confidence interval method, to determine if significant pairwise differences exist among the population means.

Question 12.87

31. Minitab output in Figure 27, for groups A, B, and C

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Figure 12.27: FIGURE 27

12.2.31

Test 1: . 95% confidence interval for is (–5.642, 0.309), which does contain zero, so we do not reject for level of significance . Test 2: . 95% confidence interval for is (–7.642, −1.691), which does not contain zero, so we reject for level of significance . Test 3: . 95% confidence interval for is (–4.976, 0.976), which does contain zero, so we do not reject for level of significance .