Students at a local middle school were randomly selected to participate in a reading comprehension program. The program is designed to increase their reading comprehension. A total of 21 students each took a pretest before the program and posttest after the program. The mean differences in the posttest and pretest is 24. The administration decided that all students in the school would participate in the program next school year. Let µA denote the mean score of the posttest and µB denote the mean score of the pretest for all students in the school. The 98 percent confidence interval estimate of the difference between the means for all students is (17, 31). What is an appropriate interpretation of the confidence interval? a

For any µA and µB with (µA µB) ≥ 23, the sample result is quite likely.

b

µA is greater than µB, with a probability of 0.98.

c

µA is less than µB, with a probability of 0.98.

d

For any µA and µB with 17 < (µA − µB) < 31, the sample result is quite likely.

e

µA is approximately 31 and µB is approximately 17.