Question 7 10 pts Data collected by a psychology professor over a four-year period examined the relationship between class attendance and average test grades in introductory psychology. Results revealed that the correlation between the number of classes attended was positively correlated with the students' average test grade over the course of the semester (r = 0.35). (a) What is the proportionate reduction in error, or r2, for predicting average test grade from the number of classes attended? (b) Explain in words (1 - 2 senstences) what this r2 means for this set of data