College football players trying out for the NFL are given the Wonderlic standardized intelligence test. The file Wonderlic lists the average Wonderlic scores of football players trying out for the NFL and the graduation rates for football players at the schools they attended. (Data extracted from S.Walker, "The NFL's Smartest Team," TheWall Street Journal, September 30, 2005, pp. W1, W10.)
a. Compute and interpret the coefficient of correlation, r.
b. At the 0.05 level of significance, is there a significant linear relationship between the average Wonderlic score of football players trying out for the NFL and the graduation rates for football players at selected schools?
c. What conclusions can you reach about the relationship between the average Wonderlic score of football players trying out for the NFL and the graduation rates for football players at selected schools?