Construct 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 the confidence interval estimate to include zero? Why or why not?
In exercise
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.