In: Statistics and Probability
Using the set of scores below, determine if the difference between the two sets of scores is significant at alpha .05, two tailed. Determine this through the paired t-test. Show the 5 steps of hypothesis testing. Solve manually, by hand showing all steps. Do not use SPSS or excel.
X Y
3 8
8 7
5 6
7 7
6 6
8 9
At 5% level of significance we want to test the claim that if there is a significant difference between the two sets of scores.
The hypothesis testing problem is:
The data is
X | Y | d=X-Y | d^2 |
3 | 8 | -5 | 25 |
8 | 7 | 1 | 1 |
5 | 6 | -1 | 1 |
7 | 7 | 0 | 0 |
6 | 6 | 0 | 0 |
8 | 9 | -1 | 1 |
Total | -6 | 28 |
The mean of the difference is:
The standard deviation is:
The test statistic is:
Here degrees of freedom for the test are df=n-1=5
Therefore, the t critical value at 5% level of significance for two tailed test is:
### By using t table
Since the test statistic t=-1.27864>-2.571, We are unable to reject the null hypothesis.
Therefore, we don not have enough evidence to claim that there is a significant difference between the two sets of scores.