For academic year, all the students at a high school were observed. The aim was to test the hypothesis that studying more increased a student’s chances of earning a higher grade. It turned out that the students who spent the most time studying did not earn grades as high as did many students who studied less. Nonetheless, the researchers concluded that the results of the observation supported the initial hypothesis. Which one of the following, if true, most helps to explain why the researchers drew the conclu-sion described above?

#### Options

The students who spent the most time studying earned higher grades than did some students who studied for less time than the average.

The students tended to get slightly lower grades as the academic year progressed.

In each course, the more a student studied, the better his or her grade was in that course.

The students who spent the least time studying tended to be students with no more than average involvement in extra-curricular activities.

#### Solution

**In each course, the more a student studied, the better his or her grade was in that course.**

**Explanation:**

The hypothesis states that the more a student studies, the higher are his grades. The observation is that the students who spent most time studying did not get grades as high as did many students who studied less. The hypothesis compares the performance of a student who studies say 4 hours a day with the same student if he/she were to study 6 hours a day. However, the observation compares the performance of one student with another. 'In each course, the more a student studied, the better his or her grade was in that course.' helps in explaining why the observation does not undermine the hypothesis. It says when a student studies more, his performance improves relative to his own past performance.