Television is regarded by many as a prime culprit for the difficulty many students have in performing well in school. The article “The Impact of Athletics, Part- Time Employment, and Other Activities on Academic Achievement” (Journal of College Student Development [1992]: 447– 453) reported that for a random sample of n = 528 college students, the sample correlation coefficient between time spent watching television (x) and grade point average (y) was r = 2.26.
a. Does this suggest that there is a negative correlation between these two variables in the population from which the 528 students were selected? Use a test with significance level .01.
b. Would the simple linear regression model explain a substantial percentage of the observed variation in grade point average? Explain your reasoning.