A study of 1,649 college students suggests a link between Facebook use and grade point average. Freshmen reporting a higher use of Facebook had lower grade point averages than freshmen reporting a lower use of Facebook. (Data extracted from R. Junco, "Student class standing, Facebook use, and academic performance," Journal of Applied Developmental Psychology, 2015.)
a. Does the study suggest that use of Facebook and grade point average are positively correlated or negatively correlated?
b. Do you think that there might be a cause-and-effect relationship between use of Facebook and grade point average? Explain.