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 92 bank customer waiting times is ñ = 5.43. If we let u denote the mean of all possible bank customer waiting times using the new system and assume that o equals 2.45: (a) Calculate 95 percent and 99 percent confidence intervals for u. (Round your answers to 3 decimal places.) [ 95 percent confidence intervals for u is 99 percent confidence intervals for u is ]. ]. (b) Using the 95 percent confidence interval, can the bank manager be 95 percent confident that u is less than six minutes? Explain. 95 percent interval is 6.

Answer 1

Aus! The 95%, confidence Corteomal for M = 8+ z* তি € 5.43 of 1.96 x 2.45 592 (4.929,5.931) b The 99%, confidence évberval for M = x + Z ho ho 5:43 7 2.576 % 2145 92 ---(4.772,6.088) Yes, the 95% confident inetrul is less than 6. CS Scanned with CamScanner