Final answer:
According to the study mentioned in the article, training has a substantial positive effect on sales.
Step-by-step explanation:
The study mentioned in the article shows that training has a substantial positive effect on sales. The study examined various types of training, including self-instruction, lecture and discussion, and computer-assisted training. The results of the study indicated that training was effective in improving sales performance, as evidenced by the immediate response of employees, achievement of learning outcomes, behavioral measurements by supervisors, and business results such as productivity and profits.