SOLUTION: I don't understand how to do these, I have researched all day. Please help. Which is relatively better a score of 84 on a psychology test or a score of 47 on an economics test?

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Question 757445: I don't understand how to do these, I have researched all day. Please help.
Which is relatively better a score of 84 on a psychology test or a score of 47 on an economics test? Scores on the psychology test have a mean of 91 and a standard deviation of 10. Scores on the economics test have a mean of 51 and a standard deviation of 6.
A. The psychology test score is relatively better because its z score is less than the z score for the economics test score.
B. The economics test score is relatively better because its z score is greater than the z score for the psychology test score.
C. The psychology test score is relatively better because its z score is greater than the z score for the economics test score.
D. The economics test score is relatively better because its z score is less than the z score for the psychology test score.
Answer by John10(297) About Me  (Show Source):
You can put this solution on YOUR website!
Which is relatively better a score of 84 on a psychology test or a score of 47 on an economics test? Scores on the psychology test have a mean of 91 and a standard deviation of 10. Scores on the economics test have a mean of 51 and a standard deviation of 6.
A. The psychology test score is relatively better because its z score is less than the z score for the economics test score.
B. The economics test score is relatively better because its z score is greater than the z score for the psychology test score.
C. The psychology test score is relatively better because its z score is greater than the z score for the economics test score.
D. The economics test score is relatively better because its z score is less than the z score for the psychology test score.
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For this problem, you need to find the z-score for EACH test to compare which one is better.
To find z, apply the formula z = (score - mean)/standard deviation.
I help you on the first z-score for psychology:
z = (84 - 91)/10 = -0.7
Then you can find the z-score for economy score. Then you compare them. The higher z-score means relatively better.
Good luck! John