t-test analysis
Assignment 4 (t test) Worksheet
· Round each decimal answer to two digits or you will get incorrect results on your work and your will get no points in D2L. Only the precise answer obtained after rounding to the two decimal places will be correct.
Below are results of an independent samples t-test analysis of Group A and Group B’s scores on a stress test (higher score = more stress).
Group
N
Mean
Standard Deviation
T
df
Significance
(2-tailed)
Group A
15
12.20
1.74
-2.64
28
.014
Group B
15
14.00
2.00
Based on this t-test analysis, answer each of the questions below.
1) For the following statement, what number specifies the calculated t value?
t(28) = -2.64, p < .05
A) 28
B) .05
C) -2.64
D) t
2). In the case of an independent samples t-test, the df is determined by
A). Adding the sample n of both groups.
B) Subtracting 2 from each sample n.
C). Subtracting 1 from each sample n and then adding the results. df= (n1-1) + (n2-1)
D). None of the above.
3. The mean score for group A = ___________
4. The standard deviation for Group B = ___________
5. What is the absolute score of the critical t value displayed in table c.2 of your text for 28
degrees of freedom at the .05 alpha level? tcrit ± ______________________.
6. The actual significance level (p-value) of the calculated t test is ___________
7. Which statement about the two groups is correct?
a. There was no significant difference between group A and group B.
b. Group A displayed significantly more stress than group B.
c. Group B displayed significantly more stress than group A.
d. Group B displayed significantly less stress than group A.