Question

A group of researchers conducted a study to determine whether the final grade in an honors section of introductory psychology was related to a student’s performance on a test of math ability administered for college entrance. The researchers looked at the test scores of 200 students (n= 200) and found a correlation of r= .45 between math ability scores and final course grade. The proportion of the variability seen in final grade performance that can be predicted by math ability scores is ____.

A) 0.48

B) 0.20

C) 0.45

D) 0.90

Answer 1

Solution:

Given , the correlation coefficient r = 0.45

The proportion of variability seen in y that can be predicted by x is given by r²

The proportion of the variability seen in final grade performance that can be predicted by math ability scores

= r²

= 0.45²

= 0.2025

= 0.20

Answer : 0.20

Option B is correct