A sales manager examined age data, education level, a personality factor that indicated level of introvertedness/extrovertedness, and level of sales attained by the company's 120-person salesforce. The technique used was regression analysis. After analyzing the data, the sales manager said, "It is apparent to me that the higher the level of education and the greater the degree of extrovertedness a salesperson has, the higher will be an individual's level of sales. In other words, a good education and being extroverted cause a person to sell more." Would you agree or disagree with the sales manager's conclusions? Why?