Problem 11.16 analyzed the number of weekly hours worked per person at five different plants. An F value of 3.10 was obtained with a probability of .0266. Because the probability is less than .05, the null hypothesis is rejected at α = .05 There is an overall difference in the mean weekly hours worked by plant. Which pairs of plants have significant differences in the means, if any? To answer this question, a Minitab computer analysis was done. The data follow. Study the output in light of problem 11.16 and discuss theresults.

Tukey 95% Simultaneous Confidence Intervals All Pairwise Comparisons Individual confidence level 99.32% Plant 1 subtracted from: Lower Center Upper 2.466 3.598 14.939 4.499 Plant 5-12.721 0.921 10.880 Plant 2-17.910 -7.722 Plant 3 Plant 421.8308.665 -7.743 -15 15 30 Plant 2 subtracted from: Lower 0.180 11.320 22.460 Center Plant 3 Plant 4-13.935 0.944 12.048 Plant 5 -4.807 6.801 18.409 Plant 3 subtracted from: 15 15 30 Lower Center Upper Plant 5-17.1514.519 8.113 Plant 4 subtracted from: 15 15 30 Lower -6.547 Center Upper Plant 5 -15 15 30