A clinical psychologist is interested in the relationship between testosterone level in married males and the quality of their marital relationship. A study is conducted in which the testosterone levels of eight married men are measured. The eight men also fill out a standardized questionnaire assessing quality of marital relationship. The questionnaire scale is 0-25, with higher numbers indicating better relationships. Testosterone scores are in nanomoles/liter of serum. The data are shown below.
|
Subject number
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
|
Relationship score
|
24
|
15
|
15
|
10
|
19
|
11
|
20
|
19
|
|
Testosterone level
|
12
|
13
|
19
|
25
|
9
|
16
|
15
|
21
|
Construct a scatter plot of the data and describe the nature and direction of the relationship between the two variables
Compute the appropriate correlation coefficient between the two variables
Determine the least-squares regression line for predicting relationship score from testosterone level Determine the predicted relationship scores of all the subjects Determine the error scores in predicting relationship score from testosterone level Test whether the model is better than the null Test whether the regression coefficient is different from zero