CONDITIONAL PROBABILTY 1. The management of a company finds that 30% of the secretaries hired are unsatisfactory. A test is created to help screen secretarial applicants. One hundred employed secretaries are chosen at random and are given the new test. Out of these, 90% of the satisfactory secretaries pass the test and 20% of the unsatisfactory secretaries pass. Based on these results… a) if a person applies for a secretarial job, takes the test, and passes it, what is the probability that he/she will be a satisfactory secretary? b) if the applicant fails the test, what is the probability that he/she will be an unsatisfactory secretary? 2. A bag contains two one‐dollar bills, a five‐dollar bill, and a ten‐dollar bill. A player draws bills one at a time without replacement from the bag until a ten‐dollar bill is drawn. Then the game stops. All bills are kept by the player. a) What is the probability of winning $16? b)
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