Students taking a multiple-choice exam rarely guess randomly. They usually can rule out some answers as preposterous and identify others as good candidates. Moreover, even students who have never taken Psychology 1 would probably know who Pavlov was, or what we mean by sibling rivalry. Suppose that the exam above was our Psychology 1 exam, where each question had four alternative choices.
(a) What would you conclude if the student got a score of 70?
(b) How high a score would the student have to get so that you were 95% confident that the student wasn’t just guessing at random?