A bank with branch in commercial district and branch in residential district wants to find out if there is difference in average waiting time between two branches (Residential District and Commercial District). Five customers are chosen from each branch randomly and the waiting time for each and every customer is measured (total of 10 customers). The following data was collected:
Residential Commercial
8.6 6
7.1 5.5
7.1 3.1
5.8 5.8
8.4 5
(a) Based upon the above information, at the .05 level of significance, is there evidence of difference in the mean waiting time between two branches?
(b) What assumptions do you've to make about two populations in order to justify the employ of your test in part (a)?