A bank with a branch located in a commercial district of a city has the business objective of improving the process for serving customers during the noon-to-1 PM lunch period. To do so, the wating time (defined as the number of minutes that elapses from when the customer enters the line until he or she reaches the teller window) needs to be shortened to increase customer satisfaction. Another Bank in the area also concerned with the noon-to-1 PM lunch period. A random sample of 15 customers is selected from each bank and the waiting times are the following: Bank 1 Bank 2
4.21 9.66
5.55 1.9
3.02 8.02
5.13 2.79
4.77 8.73
2.34 3.82
3.54 8.01
3.2 8.35
4.51 0.49
6.1 6.68
0.38 5.64
6.12 4.08
6.46 6.17
6.19 9.91
4.79 5.47
Is there evidence of a difference in the variability of the waiting time between the two branches? (alpha = 0.10)
a. What test should you run?
b. State the null and alternate hypotheses.
c. Find the critical value.
d. Compute the value of the test statistic.
e. What is your decision regarding the null hypotheses? Interpret the result.