Consider a scenario where two classes take the same exam and the performance in
ID: 3125102 • Letter: C
Question
Consider a scenario where two classes take the same exam and the performance in these two classes is as follows:
Class A is taught on Mondays and therefore represents the students who take weekday classes: the average grade is 82 points, the standard deviation is 11, and the number of students taking the exam is 80
Class B is taught on Saturdays and therefore represents the students who take weekend classes: the average grade is 87 points, the standard deviation is 8, and the number of students taking the exam is 90.
We can assume that the standard deviations are those of the two populations.
Based on this, can we reject with a 90% level of significance the hypothesis that the average performance of the weekend students (Class B), exceeds that of the weekday students (Class A) by at least 10 points?
Question 1 options:
a) Yes we reject the null hypothesis that the average performance of Class B exceeds the average performance of Class A by at least 10 points
b) We fail to reject the null hypothesis that the average performance of Class B exceeds the average performance of Class A by at least 10 points
c) Not enough information is provided.
a) Yes we reject the null hypothesis that the average performance of Class B exceeds the average performance of Class A by at least 10 points
b) We fail to reject the null hypothesis that the average performance of Class B exceeds the average performance of Class A by at least 10 points
c) Not enough information is provided.
Explanation / Answer
Set up hypotheses as:
H0: mu2 - mu1 <=10
Ha: mu2- mu1 >10
p value = .000493.
The result is significant at p < .05.
Hence accept alternate that mean of class B is greater than class B by atleast 10 points.
Class A B Mean2-Mean1-10 Mean 82 87 -5 sigma 11 8 n 80 90 Pooled var 2.223611 std error 1.491178 t stat -3.35305 df 169