Compute the following probabilities by using the hypergeometric formula:

a. Th e probability of x 3 if N 11, A 8, and n 4

b. Th e probability of x 2 if N 15, A 5, and n 6

c. Th e probability of x 0 if N 9, A 2, and n 3

d. Th e probability of x 4 if N 20, A 5, and n 7