One of the criteria statistics professors use to select a textbook is the number of exercises provided. One particular topic in statistics is selected: the t-test of the mean. A random sample of 15 professors is asked how many exercises students should do in order to master the topic. The sample average was 19.2, with a standard deviation of 5.2. A random sample of 20 students who demonstrated that they had mastered the topic by successfully completing some related questions was selected from these professors' classes. The students were asked how many exercises they actually completed for this topic. The sample average was 12.3, with a standard deviation of 3.6.Is there evidence, at the 1% level of significance, that the professors overestimate the number of exercises that students need to do to master this topic? You may assume the sample data for both professors and students appear normally distributed.
Answer to relevant QuestionsConstruct a 99% confidence interval estimate for the difference in the number of exercises professors think are necessary and the number the students deem necessary for the situation described in Exercise 12. Do you expect ...A financial advisor is concerned that the time she has to spend with her clients has increased because of the increasing complexity of the investment products available. The advisor asks her assistant to keep track of ...Why is it important, when conducting a Wilcoxon Rank Sum Test using Appendix 5 on page 582, to calculate W from the smallest sample? Refer to your analysis for Develop Your Skills 11.2, Exercise 6 (page 420). Which of the locations for a new upscale coffee store would be best? The owner of a winery is wondering whether the average purchase of visitors to her winery differs according to age. She asks the cashiers to keep track of a random sample of purchases by customers in three age groups: under ...
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