=+an average time of 15 minutes + > - 3 minutes is acceptable by most of the customers. L’Arpège then did a sample study of 5 nights, where each night 5 observations of food serving (i.e., time between receiving the order and serving the food) were made. The observed times are listed in the table below:

SAMPLE

(n 5 5) OBSERVATIONS (MINUTES)

1 14 13 21 14 15 2 15 16 20 17 14 3 15 15 15 13 11 4 16 17 15 18 14 5 17 15 16 14 15