Question

Which is relatively better: a score of 73 on a psychology test or a score of 41 on an economics test? Scores on the psychology test have a mean of 86 and a standard deviation of 15. Scores on the economics test have a mean of 48 and a standard deviation of 7.Choose the correct answer below.(A) The economics test score is relatively better because its z score is less than the z score for the psychology test score.(B) The psychology test score is relatively better because its z score is less than the z score for the economics test score.(C) The economics test score is relatively better because its z score is greater than the z score for the psychology test score.(D) The psychology test score is relatively better because its z score is greater than the z score for the economics test score.

Answer 1

The correct option is: (D) The psychology test score is relatively better because its z score is greater than the z score for the economics test score.

Explanation:

Consider the provided information.

For psychology test:

Scores on the psychology test have a mean of 86 and a standard deviation of 15.

Use the Z score test as shown:

`z=(x-\mu)/(\sigma)`

Substitute x=73, μ=86 and σ=15 in the above formula.

`z=(73-86)/(15)`

`z=-0.866`

For economics test:

Scores on the economics test have a mean of 48 and a standard deviation of 7.

Use the Z score test as shown:

`z=(x-\mu)/(\sigma)`

Substitute x=41, μ=48 and σ=7 in the above formula.

`z=(41-48)/(7)`

`z=-1`

The Z score of psychology test is greater than the Z score of economic test.

Thus, the correct option is: (D) The psychology test score is relatively better because its z score is greater than the z score for the economics test score.