To test whether extracurricular activity is a good predictor ofcollege success, a college administrator records whether studentsparticipated in extracurricular activities during high school andtheir subsequent college freshman GPA.
Extracurricular
Activity | College
Freshman GPA |
|---|
| Yes | 3.48 |
| Yes | 3.30 |
| Yes | 3.87 |
| Yes | 3.75 |
| No | 3.00 |
| No | 3.86 |
| No | 3.39 |
| No | 2.75 |
| No | 3.86 |
| No | 2.76 |
(a) Code the dichotomous variable and then compute apoint-biserial correlation coefficient. (Round your answer to threedecimal places.)
2. A psychologist noted that people have more difficultysleeping in a bright room than in a dark room. She measured whetherthe intensity of the light could predict the time it took a sampleof 4 participants to fall asleep. The data for this hypotheticalstudy are listed in the following table.
Intensityof
Light (in watts) | Time ItTook to
Sleep (in minutes) |
|---|
| X | Y |
|---|
| 5 | 13 |
| 10 | 20 |
| 20 | 32 |
| 40 | 37 |
Compute an analysis of regression for this hypothetical study.(Round your answers to two decimal places.)
Sourceof
Variation | SS | df | MS | Fobt |
|---|
| Regression | | | | |
| Residual(error) | | | | |
| Total | | | | |
3.
