Recall that a bank manager has developed a new system to reduce the time customers spend waiting to be served by tellers during peak business hours.

Recall that a bank manager has developed a new system to reduce the time customers spend waiting to be served by tellers during peak business hours. The mean waiting time during peak business hours under the current system is roughly 9 to 10 minutes. The bank manager hopes that the new system will have a mean waiting times in table 1.8 is x ̃ = 5.46. If we let μ denote the mean of all possible bank customer waiting times using the new system and assume that σ equals 2.47: