One of the authors came across an article (USA Today, 2008) that said that on average Americans have visited 16 states in the United States. In a survey of 50 students in her introductory statistics class, she found the average number of states the students had visited to be 9.48 and the standard deviation to be 7.13. The data were not strongly skewed.
a. Identify the observational unit for this study.
b. Identify the variable of interest and whether it is categorical or quantitative.
c. Clearly the sample is not a randomly selected sample but a convenience sample. With this in mind, would it still be okay to treat the sample as representative of the population of students at the author’s school with regard to “number of states visited”? Explain.
d. Regardless of your answer to part (c), state the null and the alternative hypotheses in symbols, to test whether the average number of states all students at the author’s school have visited is different from 16.

e. Use the 2SD approach to find a 95% confidence interval for the average number of states all students at the a uthor’s school have visited.