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Hi professor
I am confused with the results of #36 on the hw. The confidence interval came out to be 1.21 and 7.54. So the results are that there is a significant difference because they are both positive. However, since both are positive results, doesn't that mean that the first mean is bigger. And according to the problem, the 1st mean is the 1st score before retaking the exam. However, the results show that the students get a better score after retaking the exam (which is the 2nd mean in the problem). Can you please explain the results.

Thank you

Posted to STATS 2 on Tuesday, October 15, 2013   Replies: 2

Professor Mcguckian
10/15/2013
11:06 PM EST

Hi Shirley,

The subtaction to get the differences in this problem was done (Second score - First Score), so that is why the positive interval indicates the second scores are higher.

Hope that clears it up,

Professor McGuckian

.
10/15/2013
11:19 PM EST
Great! Thank you