Question

To test the effectiveness of a business school preparation course, 8 students took a general business test before and after the course. The results are given below Exam Score Exam Score Student Before Course (1) After Course (2) 1 530 670 2 690 770 3 910 1,000 700 710 450 550 6 820 870 7 820 770 630 610 Referring to the above information, the number of degrees of freedom is O 14 O 13 Os O 7

Answer 1

This is a paired t-test also called dependent sample t-test used to determine whether the mean difference between two sets of observations is zero. Here the two observations are from the same individual or subject, in different conditions. When there are "n" individuals involved in the experiment then the degree of freedom for the test is "n-1".

Here in the above test, there are 8 students hence the degree of freedom is 7.