Please do in Excel
A bank with a branch located in a commercial district of a cityhas the business objective of improving the process for servingcustomers during the noon-to-1 p.m. lunch period. To do so, thewaiting time (defined as the number of minutes that elapses fromwhen the customer enters the line until he or she reaches theteller window) needs to be shortened to increase customersatisfaction. A random sample of 15 customers is selected and thewaiting times are collected and stored in Bank1 . These dataare:
4.21 5.55 3.02 5.13 4.77 2.34 3.54 3.20
4.50 6.10 0.38 5.12 6.46 6.19 3.79
Suppose that another branch, located in a residential area, isalso concerned with the noon-to-1 p.m. lunch period. A randomsample of 15 customers is selected and the waiting times arecollected and stored in Bank2 . These data are:
9.66 5.90 8.02 5.79 8.73 3.82 8.01 8.35
10.49 6.68 5.64 4.08 6.17 9.91 5.47
a. Is there evidence of a difference in the variability of thewaiting time between the two branches? (Use a = 0.05.)
b. Determine the p-value in (a) and interpret its meaning.
c. What assumption about the population distribution of eachbank is necessary in (a)? Is the assumption valid for thesedata?
d. Based on the results of (a), is it appropriate to use thepooled-variance t test to compare the means of the twobranches?
