Students who study statistics in college tend to score higher on the Graduate Record Examinations (GRE) math section than students who do not study statistics. Which is true?
A) This shows that studying statistics improves your knowledge for the GRE.
B) Students who choose to study statistics are probably already good at math, so we can't conclude anything about cause-and-effect.
C) This makes no sense because you can't compute the correlation between studying statistics and GRE math section test scores.
D) There is a positive correlation between whether or not a student studied statistics and the student's GRE math section test score.

Question

Quizplus · Accepted Answer

The fact that students who study statistics tend to score higher on the GRE math section could be due to two possible reasons: (1) studying statistics improves GRE math performance or (2) students who are good at math are more likely to study statistics. Because we cannot control for the students' prior math ability, we cannot conclude that studying statistics causes higher scores. Therefore, B is the correct choice.

Students Who Study Statistics in College Tend to Score Higher