Katz, Lautenschlager, Blackburn, and Harris (1990) examined the performance of 28 students, who answered multiple choice items on the SAT without having read the passages to which the items referred....

Katz, Lautenschlager, Blackburn, and Harris (1990) examined the performance of 28 students, who answered multiple choice items on the SAT without having read the passages to which the items referred. The mean score (out of 100) was 46.6, with a standard deviation of 6.8. Random guessing would have been expected to result in 20 correct answers.

a. Were these students responding at better-than-chance levels?

b. If performance is statistically significantly better than chance, does it mean that the SAT test is not a valid predictor of future college performance?