Needing help with this practice question.

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 time that is less than six minutes. The mean of the sample of 100 bank customer waiting times in Table 1.9 is X = 5.46. If we let / denote the mean of all possible bank customer waiting times using the new system and assume that o equals 2.47: Click here for the Excel Data File (a) Calculate 95 percent and 99 percent confidence intervals for . (Round your answers to 3 decimal places.) 95 percent confidence intervals for u is 4.976 V 5.944 1. 99 percent confidence intervals for u is 4.834 X 6.096 1