Ben has created two versions of exam papers for his class. Students in his class have been randomly selected and each of them was assigned to attempt one of the two versions of the exam papers. The table below shows the amount of time (in minutes) each student has spent completing the exam.

A 88 83 70 90 88 55 41 114 90 88 71 92 60 45 67 48 B 55 57 67 58 62 60 39 56 35 49 56 45 52 60 49 67 a. The standard deviation of the amount of time needed to complete Version A is minutes. (Round to two decimal places.) b. The F statistic that allows to test the equality of the two population variances of the amount of time needed is (Round to two decimal places.) c. To test the hypotheses: H : 62 (A) = 2 (B) H: 62 (A) # 62 (B) The critical values of the F statistics for the rejection region are and if a = 10%. (Round to two decimal places.) d. The 95% confidence interval for the difference between the mean amount of time needed to complete the exam papers is [ J. (Round to two decimal places.)