A random sample of 12 college baseball players participated in a special weight-training program in an attempt to improve their batting averages. The program lasted for 20 weeks immediately prior to the start of the baseball season. The average number of hours per week and the change in their batting averages from the preceding season are as follows:
(8.0, 10) (20.0, 100) (5.4, -10) (12.4, 79) (9.2, 50) (15.0, 89) (6.0, 34) (8.0, 30) (18.0, 68) (25.0, 110) (10.0, 34) (5.0, 10)
a. Plot the data. Does it appear that the weight training program was successful?
b. Estimate the regression equation.