Carmine reads an article that says that male college students study less than female college students. Carmine wonders if this is really so. He asks 20 randomly selected students-10 males and 10 females-from his coed dorm to record their study times for a period of 4 weeks. Here are the students' average weekly study times, to the nearest half-hour:
| Males |
Females |
|
13.5
|
15.5
|
|
6.5
|
10.0
|
|
8.0
|
10.5
|
|
14.5
|
7.0
|
|
12.5
|
13.0
|
|
16.0
|
12.5
|
|
12.0
|
11.0
|
|
9.5
|
8.5
|
|
7.0
|
8.0
|
|
11.5
|
13.0
|
a. Is the research hypothesis in this study directional or nondirectional?
b. State the research hypothesis.
c. you t and compare it with the tabled critical t at the .05 a level. Can you reject the null hypothesis?
d. Do you think these samples are representative of all college males and females? To what populations can Carmine rightfully infer the results?