In: Statistics and Probability
***SHOW SPSS**
A researcher is interested to learn if there is a linear relationship between the hours in a week spent exercising and a person’s life satisfaction. The researchers collected the following data from a random sample, which included the number of hours spent exercising in a week and a ranking of life satisfaction from 1 to 10 ( 1 being the lowest and 10 the highest).
Participant |
Hours of Exercise |
Life Satisfaction |
1 |
3 |
1 |
2 |
14 |
2 |
3 |
14 |
4 |
4 |
14 |
4 |
5 |
3 |
10 |
6 |
5 |
5 |
7 |
10 |
3 |
8 |
11 |
4 |
9 |
8 |
8 |
10 |
7 |
4 |
11 |
6 |
9 |
12 |
11 |
5 |
13 |
6 |
4 |
14 |
11 |
10 |
15 |
8 |
4 |
16 |
15 |
7 |
17 |
8 |
4 |
18 |
8 |
5 |
19 |
10 |
4 |
20 |
5 |
4 |
Diet |
|||
Exercise |
<30% fat |
30% - 60% fat |
>60% fat |
<60 minutes |
4 |
3 |
2 |
4 |
1 |
2 |
|
2 |
2 |
2 |
|
4 |
2 |
2 |
|
3 |
3 |
1 |
|
60 minutes |
6 |
8 |
5 |
or more |
5 |
8 |
7 |
4 |
7 |
5 |
|
4 |
8 |
5 |
|
5 |
6 |
6 |
Solution:
Here, we have to develop the regression model for the prediction of the dependent or response variable rating of life satisfaction based on the independent or explanatory variable hours of exercise in a week. The descriptive statistics and regression model by using SPSS is given as below:
Descriptive Statistics |
|||
Mean |
Std. Deviation |
N |
|
Life Satisfaction |
5.0500 |
2.48098 |
20 |
Hours of Exercise |
8.8500 |
3.66024 |
20 |
Correlations |
|||
Life Satisfaction |
Hours of Exercise |
||
Pearson Correlation |
Life Satisfaction |
1.000 |
-.103 |
Hours of Exercise |
-.103 |
1.000 |
|
Sig. (1-tailed) |
Life Satisfaction |
. |
.332 |
Hours of Exercise |
.332 |
. |
|
N |
Life Satisfaction |
20 |
20 |
Hours of Exercise |
20 |
20 |
Variables Entered/Removedb |
|||
Model |
Variables Entered |
Variables Removed |
Method |
1 |
Hours of Exercisea |
. |
Enter |
a. All requested variables entered. |
|||
b. Dependent Variable: Life Satisfaction |
Model Summary |
||||
Model |
R |
R Square |
Adjusted R Square |
Std. Error of the Estimate |
1 |
.103a |
.011 |
-.044 |
2.53529 |
a. Predictors: (Constant), Hours of Exercise |
ANOVAb |
||||||
Model |
Sum of Squares |
df |
Mean Square |
F |
Sig. |
|
1 |
Regression |
1.252 |
1 |
1.252 |
.195 |
.664a |
Residual |
115.698 |
18 |
6.428 |
|||
Total |
116.950 |
19 |
||||
a. Predictors: (Constant), Hours of Exercise |
||||||
b. Dependent Variable: Life Satisfaction |
Coefficientsa |
||||||
Model |
Unstandardized Coefficients |
Standardized Coefficients |
t |
Sig. |
||
B |
Std. Error |
Beta |
||||
1 |
(Constant) |
5.671 |
1.516 |
3.740 |
.001 |
|
Hours of Exercise |
-.070 |
.159 |
-.103 |
-.441 |
.664 |
|
a. Dependent Variable: Life Satisfaction |
Questions
Part a
Find the mean hours of exercise per week by the participants.
The required mean hours of exercise per week by the participants is given as 8.85 hours.
Part b
Find the variance and standard deviation of the hours of exercise per week by the participants.
The variance and standard deviation of the hours of exercise per week by the participants is given as below:
Standard deviation = 3.66024
Variance = 3.66024^2 = 13.397357
Part c
Run a bivariate correlation to determine if there is a linear relationship between the hours of exercise per week and the life satisfaction. Report the results of the test statistic using correct APA formatting.
The correlation coefficient between the two variables hours of exercise per week and the life satisfaction is given as -0.103. This means, there is a very low or weak negative linear relationship or association exists between the given two variables. The corresponding p-value from the above SPSS output is given as 0.332 which is greater than the level of significance or alpha value 0.05, so we do not reject the null hypothesis and conclude that this correlation coefficient is not statistically significant. This means, there is no statistically significant relationship exists between the hours of exercise per week and the life satisfaction.
Part d
Run a linear regression on the data. Report the results, using correct APA formatting. Identify the amount of variation in the life satisfaction ranking that is due to the relationship between the hours of exercise per week and the life satisfaction (Hint: the R2 value)
From the given SPSS output, the value for the correlation coefficient is given as -0.103 which indicate a low or weak negative linear association between given two variables. The value of the R square or the coefficient of determination is given as 0.011, which means about 1.1% of the variation in the dependent variable or response variable life satisfaction ranking is explained by the regression or relationship between the hours of exercise per week and the life satisfaction.
The p-value for this overall regression model is given as 0.664 which is greater than the level of significance or alpha value 0.05, so we do not reject the null hypothesis. There is insufficient evidence to conclude that the given regression model is statistically significant. So, we cannot use this regression model for the prediction of the dependent variable life satisfaction based on independent variable hours of exercise. The slope of the regression equation is not statistically significant as the corresponding p-value is given as 0.664 which is greater than alpha value 0.05.
Part e
Report a model of the linear relationship between the two variables using the regression line formula.
From the given SPSS output, the regression equation is given as below:
Life satisfaction = 5.671 – 0.070*Hours of Exercise
ŷ = 5.671 – 0.070*x