If an insurance sales representative has a 0.20 probability of making a sale on every call, what is the probability that he will make at least two sales in six calls? n n! Remark. = k k! (n - k)! for k = 0, 1, 2,..., n. 5 5! Example, = 3 3!(5 - 3)! 3!2! 5! = 5 x 4 3 2 1 (3 x 2 x 1) (2 x 1) = k=2 k=2 6 (9) k 6 (0.8)* (0.2)6-* (c) (0.2)* (0.8)*-* k k k=0 6 (0.2)* (0.8)6k (2) (0.8) (0.2)4 O 6 (2) (0.2) (0.8)4 10. P