A bank manager has developed a new system to reduce the time customers spend waiting to be served by tellers during peak business hours. Typical waiting times during peak business hours under the current system are roughly 9 to 10 minutes. The bank manager hopes that the new system will lower typical waiting times to less than six minutes and wishes to evaluate the new system. When the new system is operating consistently over time, the bank manager decides to select a sample of 100 customers that need teller service during peak business hours and analyze the data obtained to judge the efficiency of the new system.

Specifically, for each of 100 peak business hours, the first customer that starts waiting for teller service at or after a randomly selected time during the hour will be chosen for the sample. When a customer is chosen for the sample, the number of minutes the customer spends waiting for the teller service is recorded.

Problem 1. The 100 wait times described above are given in the table below as well as in the file named WaitTime.xlsx which you can download from this assignment on D2L.

a. Using from 5 to 7 classes, select appropriate class boundaries and create a frequency and relative frequency table for these data. Create a relative frequency histogram for the distribution of wait times.

b. Is the data evenly distributed over the range of values?

c. What proportion of wait times is less than six minutes as hoped for by the bank manager? Does it appear the bank manager's new system is effective?

Bank Wait Time Data