The psychology department at a certain college claims that the grades in its introductory course are distributed as follows: 10% A’s, 20% B’s, 40% C’s, 20% D’s, and 10% F’s. In a poll of 200 randomly selected students who had completed this course, it was found that 16 had received A’s; 43, B’s; 65, C’s; 48,D’s; and 28, F’s. Does this sample contradict the department’s claim at the 0.05 level?
a. Solve using the p-value approach.
b. Solve using the classical approach.