The following data relate to the scores obtained by 9 salesmen of a company in an intelligence test and their weekly sales. Test Score Weekly Sales 50 60 50 60 80 50 80 40 70 30 60 40 50 60 30 70 50 60 a) Obtain the regression equation of sales on intelligence test scores of the salesman. b) If the Intelligence test score of a salesman is 65, what would be his expected weekly sales?