In: Statistics and Probability
A researcher hypothesizes that arousal levels will be affected by meditation. The sample participates in formal meditation classes for 3 weeks, before and after which arousal is measured.
Subject BEFORE MEDITATION AFTER MEDITATION
1 72 91
2 162 155
3 145 152
4 183 190
5 123 134
6 167 157
7 76 99
8 112 104
9 124 143
10 137 156
6. Please analyze the data using the appropriate hypothesis test on SPSS and cut and paste your SPSS results here:
7. Based on your SPSS results, do you reject or fail to reject the null?
_____________________________________________
8. Please write the “statistical statement” for your SPSS results:
9. Please write your results in a “literature” or “research study” format:
Performing analysis in SPSS as well as manual
Enter the three variables named Subjects, Before,After in variable view and enter the data in data view
Go to Analyze --> Compare means --> Paired sample t test
Select before and after together and send it to Paired variable box.
Click on OK
Screenshot of SPSS
Null and Alternative Hypotheses
The following null and alternative hypotheses need to be tested:
Ho: μD = 0 i.e arousal levels are not affected by meditation
Ha: μD ≠ 0 i.e arousal levels are affected by meditation
This corresponds to a two-tailed test, for which a t-test for two paired samples be used.
Output
Paired Samples Statistics |
|||||
Mean |
N |
Std. Deviation |
Std. Error Mean |
||
Pair 1 |
Before |
130.1000 |
10 |
36.76487 |
11.62607 |
After |
138.1000 |
10 |
31.27104 |
9.88877 |
Paired Samples Correlations |
||||
N |
Correlation |
Sig. |
||
Pair 1 |
Before & After |
10 |
.945 |
.000 |
Paired Samples Test |
|||||||||
Paired Differences |
t |
df |
Sig. (2-tailed) |
||||||
Mean |
Std. Deviation |
Std. Error Mean |
95% Confidence Interval of the Difference |
||||||
Lower |
Upper |
||||||||
Pair 1 |
Before - After |
-8.00000 |
12.49000 |
3.94968 |
-16.93480 |
.93480 |
-2.025 |
9 |
.073 |
Rejection Region
Based on the information provided, the significance level is α=0.05, and the degrees of freedom are df=9.
Hence, it is found that the critical value for this two-tailed test is tc=2.262, for α=0.05 and df=9.
The rejection region for this two-tailed test is R={t:∣t∣>2.262}.
Test Statistics
The t-statistic is computed as shown in the following formula:
Decision about the null hypothesis
Since it is observed that ∣t∣=2.025 ≤ tc=2.262, it is then concluded that the null hypothesis is not rejected.
Using the P-value approach: The p-value is p=0.0735, and since p=0.0735≥0.05, it is concluded that the null hypothesis is not rejected.
Conclusion
It is concluded that the null hypothesis Ho is not rejected. Therefore, there is not enough evidence to claim that the population mean μ1 is different than μ2, at the 0.05 significance level.
Hence
arousal levels are not affected by meditation