48
(Choose 1 answer)
(See picture)
A. 0
B. 68
C. 400
D. 50
E. None of the other choices is correct.
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 Before Course (1)
Student
1
2
3
4
5
6
7
8
530
690
770
910
1,000
700
710
450
550
820
870
820
770
630
Exam Score After Course (2)
670
610
The value of the sample mean difference is if the difference scores reflect the results of the exam after the course minus the results of the exam before the course.
