Suppose that self-reports of "mathematics anxiety" correlate -.25 with performance on a mathematics test.What is the expected average score on the mathematics test for persons who are 2 standard deviations above the mean on mathematics anxiety?

Question

Quizplus · Accepted Answer

We can use the formula for expected score on a test:

Expected score = Mean + (correlation coefficient) x (standard deviation)

We are given that the correlation coefficient between mathematics anxiety and performance on a mathematics test is -.25. We know that a score 2 standard deviations above the mean corresponds to a z-score of 2, so we can use a z-score chart to find that this is equivalent to approximately 97.7% of the population.

Using the information given, we can calculate the expected score:

Expected score = Mean + (-.25) x (1 standard deviation) x (2)

Since we are given no information about the mean or standard deviation for the mathematics test, we can assume they are both 0 (since we are only interested in the expected deviation from the mean).

Expected score = 0 + (-.25) x (1) x (2) = -0.5

Therefore, persons who are 2 standard deviations above the mean on mathematics anxiety would be expected to score 0.5 standard deviations below the mean on the mathematics test. This corresponds to answer choice C.

Suppose That Self-Reports of "Mathematics Anxiety" Correlate -