In Example 8.3, suppose the organization wanted to compare the mean test scores of Catholic priests and Methodist ministers. Note that it appears based on the data that these two groups have the same variance. What is the gain in using a two-sample t-test having s2W in the denominator as opposed to using the conventional pooled t test with s2p, the average of the sample variances for the Catholic priests and Methodist ministers?
Answer to relevant QuestionsRefer to the data of Exercise 8.37. To illustrate the effect that an extreme value can have on conclusions from an analysis of variance, suppose that the weight gained by the fifth turkey in the level 2, additive B group was ...A large laboratory has four types of devices used to determine the pH of soil samples. The laboratory wants to determine whether there are differences in the average readings given by these devices. The lab uses 24 soil ...Refer to Exercise 9.13. Determine the significantly different pairs of means using the Tukey’s W with a = .05. In exercise The nitrogen contents of red clover plants inoculated with three strains of Rhizobium are given here: a. Is there evidence of a difference in the effects of the three treatments on the mean nitrogen content? Analyze the ...Refer to Exercise 8.29. a. Compare the mean discoloration scores of groups II, III, and IV to the control group. Use an experimentwise error rate of .05. b. Use the Tukey’s W procedure to compare the mean discoloration ...
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