TABLE 10-5
to Test the Effectiveness of a Business School

TABLE 10-5
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.
$$\begin{array}{l}\quad \quad \quad \quad \quad \quad \quad \quad \text { Exam Score } \quad \text { Exam Score }\\\begin{array} { c c c } \text { Student } & \text { Before Course (1) } & \text { After Course (2) } \\\hline 1 & 530 & 670 \\2 & 690 & 770 \\3 & 910 & 1,000 \\4 & 700 & 710 \\5 & 450 & 550 \\6 & 820 & 870 \\7 & 820 & 770 \\8 & 630 & 610 \\\hline\end{array}\end{array}$$
-Referring to Table 10-5, the value of the standard error of the difference scores is

A) 14.696.
B) 22.991.
C) 65.027.
D) 60.828.