"Serial exchangers" is a term that describes customers who abuse the return and exchange policies (The Wall Street Journal). For example, some customers buy an outfit, wear it once or twice, and then return it. This issue is becoming a big headache for many retailers as it adds a reverse logistics challenge to the already complex supply chain planning.

Despite the situation, the marketing team at N&M Inc. is planning to roll out an even more generous return policy to boost sales. This new policy proposed by N&M's marketing team allows customers to return a purchased item without the original receipt. While the marketing team believes that customer's return behavior will not change significantly and is ready to push this idea forward, many analysts in the supply chain department have voiced concerns in recent meetings that more "return abuse" will be the result of this policy. Management of N&M Inc. decides to experiment with this policy at 25 random stores as a pilot project before implementing such policy nationwide.

Historically, the average # return incidents for a typical store in a week is 59 (benchmark). The sample data in file "Returns.xlsx"

Return Cases 70 63 50 40 61 97 63 97 59 75 69 80 55 76 70 75 66 34 60 48 63 53 53 74 74

" shows the current number of return incidents at each of the 25 stores where the new policy has been implemented. Assume the role of a supply chain analyst at N&M Inc. and use the sample data to:conduct a one-sample hypothesis testat 5% significance level and answer the following questions:

Part A: What are the null and alternative hypotheses?

Part B: What is the p-value?What is your conclusion?

Part C: Provide a brief interpretation of the result (i.e. what the result means in the context of the problem).

Part D: Do you have any concerns about the design of this study? Briefly discuss them and propose ways to improve the study. If you have no concerns, describe why the study in its current form is already appropriate in your view.