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

Answer:

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.

Step-by-step 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:

$z=\frac{x-\mu}{\sigma}$

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

$z=\frac{73-86}{15}$

$z=-0.866$

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:

$z=\frac{x-\mu}{\sigma}$

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

$z=\frac{41-48}{7}$

$z=-1$

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.