A study is conducted to estimate the average difference in bus ridership for a large city during the morning and afternoon rush hours. The transit authority’s researcher randomly selects nine buses because of the variety of routes they represent. On a given day the number of riders on each bus is counted at 7:45 A.M. and at 4:45 P.M., with the following results.

Use the data to compute a 90% confidence interval to estimate the population average difference.Assume ridership is normally distributed.

Bus Morning Afternoon 123456789 43 41 51 49 37 44 24 32 47 46. 44 42 50 47 55 51 46 49