Question

A study was completed with 52 junior-level accounting majors enrolled in Intermediate Financial Accounting. Students took a pretest on a topic not covered in class, then were given a homework problem. Some students were given the completed solution and some were given no help. After finishing the homework, students were given a post-test. Means shown below are the knowledge gains on the post-test. Researchers thought that as the level of homework assistance increased, the test score improvement would decrease. No Solutions   Completed Solutions (n1 = 30   n2 = 22 ) (x ̅1 = 2.43   x ̅2 = 1.95 ) (s1 = 0.58   s2 = 0.32 )

1) Calculate the appropriate Standard Error.   

2) Calculate the appropriate test statistic.   

3) Calculate the degrees of freedom.   

4) Using an alpha of 0.01, what is the critical value(s)?   

5) Based on your test statistic and critical value, what decision should you make?   

6) The results are/are not statistically significant at an alpha level of ______ and we conclude __________________ (research question).

Answer 1

1)

Standard error = √{(s1^2/N1)+(s2^2/n2)}

= 0.12596776884

2)

Test statistics = (x1-x2)/standard error

Test statistics = 3.81

3)

Degrees of freedom is given by smaller of n1-1, n2-1

= 21

4)

For DF 21 and alpha 0.01, critical value is

2.518

That is if test statistics is greater than 2.518

Reject Ho

5)

As 3.81 is greater than 2.518

Reject Ho

The results are significant at an alpha level of 0.01 and we conclude that we have enough evidence to support the claim