Question

A professor in the Business department wants to know if there is a significant difference in the performance on the first exam between two different classes. One class meets in the morning while the other meets at night. The results of this test are listed below along with an excel analysis conducted at the 5% significance level (α=0.05).

t-Test: Two-Sample Assuming Equal Variances
	8 am Class	7 pm Class
Sample Mean	80.471	76.846
Sample Variance	97.51	162.14
Sample Observations	17	13
Pooled Variance	125.21
Hypothesized Mean Difference	0
df	28
t Stat (t*)	0.879
P(T<=t) one-tail	0.1934
t Critical one-tail	1.701
P(T<=t) two-tail	0.3868
t Critical two-tail	2.048

The calculated value of the test statistic (t*) in the above output is

Group of answer choices

0.879

1.701

0.005

2.048

0.065

Answer 1

This is a two tailed test

alpha = 0.05

From the given table ,

t = (x1-x2)/pooled variance

= (80.471 - 76.846)/125.21

test statistic = 0.879