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

Answer:Step-by-step explanation:So there is a 3% probability that an athlete is using EPO .The probability of showing positive on a test when you've used it is 0.99.3% x 0.99= 2.97%The probability of a positive result without EPO is 0.197% x 0,1 = 9,7 %My guess is that 2.97% + 9,7% = 12.67% or 0.1267.I don't know i may be wrong because you've put as an answer 0.0297 but if you like you may take only the first part of the answer.