Bank A and Bank B have each developed an improved process for serving customers. The waiting period from the moment a customer enters until he or she reaches the counter needs to be shortened. A random sample of 10 customers is selected from each bank and the results (in minutes) are shown in the accompanying data table. Complete parts (a) through (d).
a. Assuming that the population variances from both banks are equal, is there evidence of a difference in the mean waiting time between the two branches? (Use a=0.1.)
|Bank A||Bank B|
Find the test statistic