Question

Which is relatively​ better: a score of 6868 on a psychology test or a score of 5959 on an economics​ test? scores on the psychology test have a mean of 8585 and a standard deviation of 1515. scores on the economics test have a mean of 6565 and a standard deviation of 1010?

Answer 1

The economics test score is relatively better because of its z score is greater that the z score for the psychology test.
The calculation for this question is simply;
for psychology = (68 - 85) / 15 = -1.13
for economics = (59 - 65) / 10 = -0.6
So the answer to this question is economic is relatively better.

Answer 2

In order to get know which test is relative better, you have to use the formula to get the z score of psychology test and economics test.

Z=(raw score-sample mean)/standard deviation

Solution:

Psychology = (68 - 85) / 15 = -1.13

Economics = (59 - 65) / 10 = -0.6

Through this answer you can see that economics is closer to 0 which is the actual mean. This can be viewed through a normal distribution graph. The closer it is to 0, the relatively better it is because of it is more precise.

So economics is relatively better than psychology test.