In Chance (Spring 2002), research statisticians discussed the problem of sampling mail rooms for the presence of anthrax spores. Let x equal the number of mail rooms contaminated with anthrax spores in a random sample of 3 mail rooms selected from a population of 100 mail rooms. If 20 of the 100 mail rooms are contaminated with anthrax, researchers showed that the probability distribution for x is given by the formula

a. What is the name given to this probability distribution?
b. Specify r, N, and n for this distribution.
c. Find p (0).
d. Find p (1).
e. Find p (2).
f. Find p (3).