Question: The mean increase in word family vocabulary among students in a one-year foreign language course is 576 word families. In order to estimate the effect of a new type of class scheduling, an instructor monitors the progress of 60 students; the sample mean increase in word family vocabulary of these students is 542 word families with sample standard deviation 18 word families.

a. Test at the 5% level of significance whether the mean increase with the new class scheduling is different from 576 word families, using the critical value approach.

b. Compute the observed significance of the test.

c. Perform the test at the 5% level of significance using the p-value approach. You need not repeat the first three steps, already done in part (a).