Correlation and Multivariate

Universities report that recent research has shown that students who take more credits per semester have a higher GPA that semester. Therefore, they recommend that advisors encourage students to take more credits (such as 15-18 credits per semester).

1. If this research is correct, would the two main variables in this study produce a positive or negative correlation?

2. Generate an explanation for each of the two possible causal directions of this relationship: (a) higher credits taken cause higher grades and (b) higher grades cause higher credits taken.

3. Name and explain one possible third variable that might account for this relationship

4. How might a multiple regression analysis determine whether or not the third variable you generated is possibly responsible for the correlation between credits and grades?