Question: A library system lends books for periods of 21 days. This policy is being reevaluated in view of a possible new loan period that could be either longer or shorter than 21 days. To aid in this decision a local researcher drew a random sample of loan records and found the following loan periods: 20, 16, 10, 24, 18, 21, 15, 16. By hand, and showing the necessary calculations, use a parametric test to determine whether the actual loan period differs from 3 weeks? (3 points)

By hand, and showing your calculations, please use a non-parametric test to test the same hypothesis. What do you conclude? (2 points)