Question: The mean score on a 25-point placement exam in mathematics used for the past two years at a large state university is 14.3. The placement coordinator wishes to test whether the mean score on a revised version of the exam differs from 14.3. She gives the revised exam to 30 entering freshmen early in the summer; the mean score is 14.6 with standard deviation 2.4.
a. Perform the test at the 10% level of significance using the critical value approach.
b. Compute the observed significance of the test.
c. Perform the test at the 10% level of significance using the p-value approach. You need not repeat the first three steps, already done in part (a).