Problem 04-21 (Discrete Probability Distributions) A university found that 20% of its students withdraw without completing the introductory statistics course. Assur (a) Compute the probability that 2 or fewer will withdraw. If required, round your answer to four decimal places O (b) Compute the probability that exactly 4 will withdraw. If required, round your answer to four decimal places. (c) Compute the probability that more than 3 will withdraw. If required, round your answer to four decimal place (d) Compute the expected number of withdrawals