To test his hypothesis that students who finish an exam first get better grades, a professor kept track of the order in which papers were handed in. Of the first 25 papers, 10 received a B or better compared with 8 of the last 24 papers handed in. Is the first group better, at 5 .10?
(a) State your hypotheses and obtain a test statistic and p-value. Interpret the results.
(b) Are the samples large enough to assure normality of p1 – p2?
(c) Make an argument that early-finishers should do better. Then make the opposite argument. Which is more convincing?