Answer Happy

The management of the Diners Delight franchised restaurant chain is in the process of establishing quality-control charts for the time that its service people give to each customer. Management thinks the length of time that each customer is given should remain within certain limits to enhance service quality. A sample of six service people was selected, and the customer service they provided was observed four times. The activities that the service people were performing were identified, and the time to service one customer was recorded as noted below: Service Person 1 2 120 83 68 110 89 Determine the upper control limits for an X-chart. 3 4 5 Sample 1 200 6 Sample 2 150 85 93 86 90 65 Service Time (sec) Sample 3 175 105 130 145 75 115 Sample 4 114 75 150 175 105 125