Class rank. Choose a college student at random and ask his or her class rank in high school. Probabilities for the outcomes are Top quarter but Top half but Bottom Class rank: Top 10% not top 10% not top quarter half Probability: 0.2 0.3 0.3 ?

(a) What must be the probability that a randomly chosen student was in the bottom half of his or her high school class?

(b) To simulate the class standing of randomly chosen students, how would you assign digits to represent the four possible outcomes listed?