b. Suppose the population mean hours is later found to be 35.4 hours. The confidence interval reported by the researcher failed to cover the population mean. Discuss if there is anything wrong with the interval?

2. The property manager of a shopping mall claims that the mean score of their customer service is at least 85.Twenty-five customers were randomly selected to evaluate the customer service of the mall. The analysis via a hypothesis test shows that the P-value is less than 0.002 (i.e. p < 0.002).

a. State the null and alternative hypotheses.

b. Which distribution, normal or Student's t-distribution, is more appropriate for the hypothesis test? Why?

c. Explain the results of the hypothesis test in a way that could be understood by someone who has not studied statistics