In: Statistics and Probability
A researcher measures the relationship between Internet use (hours per week) and social interaction (hours per week) in a sample of 10 students. The following table lists the hypothetical results of this study.
| Internet Use | Social Interaction |
|---|---|
| X | Y |
| 7 | 5 |
| 9 | 5 |
| 5 | 8 |
| 6 | 7 |
| 13 | 6 |
| 5 | 7 |
| 3 | 3 |
| 5 | 5 |
| 1 | 10 |
| 12 | 2 |
(a) Compute the Pearson correlation coefficient. (Round your
answer to three decimal places.)
(b) Compute the coefficient of determination. (Round your answer to
three decimal places.)
(c) Using a two-tailed test at a 0.05 level of significance, state
the decision to retain or reject the null hypothesis.
Retain the null hypothesis. Reject the null hypothesis.
Answer:
Given Data,
A researcher measures the relationship between Internet use (hours per week) and social interaction (hours per week) in a sample of 10 students.
The following table lists the hypothetical results of this study.
| Internet Use | Social Interaction |
| X | Y |
| 7 | 5 |
| 9 | 5 |
| 5 | 8 |
| 6 | 7 |
| 13 | 6 |
| 5 | 7 |
| 3 | 3 |
| 5 | 5 |
| 1 | 10 |
| 12 | 2 |
Let the table can be modified as
| Internet Use | Social Interaction | |||
| X | Y | XY | X2 | Y2 |
| 7 | 5 | 35 | 49 | 25 |
| 9 | 5 | 45 | 81 | 25 |
| 5 | 8 | 40 | 25 | 64 |
| 6 | 7 | 42 | 36 | 49 |
| 13 | 6 | 78 | 169 | 36 |
| 5 | 7 | 35 | 25 | 49 |
| 3 | 3 | 9 | 9 | 9 |
| 5 | 5 | 25 | 25 | 25 |
| 1 | 10 | 10 | 1 | 100 |
| 12 | 2 | 24 | 144 | 4 |
X=66 |
Y=58 |
XY=343 |
X2=564 |
Y2=386 |
(a). To find the Pearson correlation coefficient:
Pearson correlation coefficient

Here n=10






Therefore Pearson Correlation=-0.498
(b).The coefficient of determination:
The coefficient of dermination=


Therefore The Coefficient of dermination=0.248
(c).
Null Hypothesis H0 :
(Two-tailed test)
Alternative Hypothesis H0 :





Therefore Test-Statistic(t)-1.873
P-value=0.216 (Since, Two-tailed test)
Given the significance level
=0.05
P-value>significance level
i.e, 0.216>0.05
Fail to reject the null hypothesis(H0).
Retain the null hypothesis.