The Professor's Response

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

  See the professor's answer below.

Professor McGukian

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

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