Many grocery stores and large retailers such as Wal-Mart and K-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? Listed below is the number of customers using the service for a sample of 15 days at the Wal-Mart on Highway 544 in Surfside, South Carolina.
120 108 112 97 120 114 118 118 108 117 91 118 92 104 104
Is it reasonable to conclude that the mean number of customers using the self-checkout system is more than 100 per day? Use the .05 significance level.