Qusetion: To test whether extracurricular activity is a good predictor of college success, a college administrator recorded whether students participated in extracurricular activities during high school and their subsequent college freshman GPA.
(a) Compute a point-biserial correlation coefficient.
(b) Using a two-tailed test at a .05 level of significance, state the decision to retain or reject the null hypothesis. Hint: You must first convert r to a t statistics.