A bank branch located in a commercial district of a city has the business objective of developing an improved process for serving customers during the noon-to-1:00 P.M. lunch period. The waiting time, in minutes, is defined as the time the customer enters the line to when he or she reaches the teller window. Data are collected from a sample of 15 customers during this hour.

4.21 5.87 3.65 5.25 4.12 2.56 3.54 3.68 4.93 6.75 0.47 5.65 6.21 6.86 3.01

a) List the five-number summary and compute the interquartile range.