Subject PostTest Score PreTest Score Difference Score 1 18 1

Subject Post-Test Score Pre-Test Score Difference Score

1        18        12         

2        43        40      

3        25        20      

4        36        33      

5        47        44      

6        46        40      

7        46        40      

21. Which statistical test would tell if the post-test scores had significantly improved over the pre-test scores?

22. Alpha is set at .05 for this one-tailed test. What are the degrees of freedom?

23. If N= 7, what is the tabled Level of Significance for this test? (Set p = .05 and use a One-Tailed Test)

24. What is the average increase or difference in scores? (Hint average of D)

25. What is the standard deviation of the difference in scores?

26. Is this difference statistically significant?

Solution

21. To test difference of two means we use t test for differences of means.

22.Alpha is set at .05 for this one-tailed test. the degrees of freedom is(n-1)=6 d.f

23.  If N= 7, the table value=2.447 (From t tables)(Set p = .05 and use a One-Tailed Test)

24. Average of two means

-4.57143

Hence difference of two means=4.57143