Question

Professor Fofana wonders if there is an association between students' grades and whether they complete extra credit in his classes. He makes a scatterplot, with the number of extra credit points earned on the x-axis and the numerical grade in his course without extra credit on the y-axis. He finds that r = 0.28. In addition to this correlation coefficient, what other information would Professor Fofana need to determine if this result is statistically significant?
a. the mean of the scores.
b. the sample size.
c. the effect size.
d. the range of responses.

Answer 1

Answer: B. The sample size

Explanation: