In the evaluation of a sales training program, a firm discovered that of 50 salespeople receiving a bonus last year, 20 had attended a special sales training program. The firm employs 200 salespeople. Let B=the event that a salesperson makes a bonus and S=the event that a salesperson attends the sales training program.

a. Find P(B), P(S), and P(SnB).

b. Assume that 40% of the salespeople attended the training program. What is the probability that a sales person makes a bonus given that the salesperson attended the sales training program, P(B | S)?

c. If the firm evaluates the training program in terms of its effect on the probability of a salesperson's receiving a bonus, what is your evaluation of the training program? Comment on whether B and S are dependent or independent events.