Reconsider Exercises 3.3.24 and 3.3.25 about the average number of states all students at the author’s school have visited. Recall that in the author’s sample of 136 students the average number of states the students had visited was 15.04 and the standard deviation was 9.26. 

a. Use the Theory-Based Inference applet to find and report an 88% confidence interval and interpret this interval in the context of the study. 

b. Explain why you cannot use a simulation-based 2SD method to find an 88% confidence interval for the average number of states all students at the author’s school have visited.

Data from Exercise 3.3.24

IPSOS opinion and public research company surveyed 2,010 adult Americans and found that, on average, Americans have visited 12 states in the United States. In a survey of 136 statistics students at the school where one of the authors teaches, the average number of states visited was 15.04 and the standard deviation was 9.26. The data were not strongly skewed.