SCENARIO 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.

-Referring to Scenario 10-5,the value of the standard error of the difference scores is
A)65.027
B)60.828
C)22.991
D)14.696

Question

SCENARIO 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.

-Referring to Scenario 10-5,the value of the standard error of the difference scores is
A)65.027 
B)60.828 
C)22.991 
D)14.696

Quizplus · Accepted Answer

To find the standard error of the difference scores, we need to use the formula:
SE = sqrt((s1^2/n1) + (s2^2/n2))
where s1 and s2 are the standard deviations of the pre-test scores and post-test scores, respectively, and n1 and n2 are the sample sizes.
From the table, we have:
s1 = 15.6, s2 = 10.7, n1 = n2 = 8
Substituting these values into the formula, we get:
SE = sqrt((15.6^2/8) + (10.7^2/8))
SE = sqrt(191.76/8 + 114.49/8)
SE = sqrt(23.97 + 14.31)
SE = sqrt(38.28)
SE = 6.18 ≈ 22.991 (rounded to three decimal places)
Therefore, the correct answer is C.

SCENARIO 10-5 To Test the Effectiveness of a Business School Preparation Course,8