Of interest is to test the hypothesis that the mean grade on test 7 for all students who attended a review session and the mean grade on test 7 for all students who did not attend a review session are the same, versus the alternative hypothesis that the mean grade on test 7 for all students who attended a review session is greater than the mean grade on test 7 for all students who did not attend a review session. State the appropriatenull and alternative hypotheses that should be tested.

(b). Consider the information and hypotheses in part (a). A simple random sample of 26 students who attended a review session was selected, and the mean grade on test 7 for this sample of 26 students was 86.5 with a standard deviation of 10.1. An independent simple random sample of 45 students who did not attend a review session was selected, and the mean grade on test 7 was 78.3 with a standard deviation of 11.2. If appropriate, use this information to test the hypotheses stated in part (a) at the = .05 level of significance.