1. Many grocery stores and large retailers such as Wal-Mart have installed self-checkout systems so shoppers can scan their own items and cash out themselves. How do customers like this service and how often do they use it? The following is the number of customers using the service for a sample of 15 days at a particular Wal-Mart in a city.

120 108 120 114 118 91 118 92

104 104 112 97 118 108 117

A. Use Excel to compute and report the mean and the standard deviation for the

sample. Copy and pasted the Excel results with your answers.

B. Conduct a test to determine whether the mean number of customers using the

self-checkout system is more than 100 per day. Use a 5% level of significance.

C. Use Excel to compute the p-values for this test. Use the p-value to reach a

decision.