Tom, Sam and Ken are wearing watches. None of the watches has the correct time. One watch says 4:00. One watch says 4:15. One watch says 4:30. Tom's watch is 10 minutes fast. Sam's watch is 20 minutes slow. Ken's watch is 5 minutes slow.

Suppose that 3% of all athletes are using the endurance-enhancing hormone epo (you should be able to simply compute the percentage of all athletes that are not using epo). for our purposes, a “positive” test result is one that indicates presence of epo in an athlete’s bloodstream. the probability of a positive result, given the presence of epo is .99. the probability of a negative result, when epo is not present, is .90. what is the probability that a randomly selected athlete tests positive for epo? 0.0297