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.