Which function has an inverse that is also a function? {(–4, 3), (–2, 7), (–1, 0), (4, –3), (11, –7)}
{(–4, 6), (–2, 2), (–1, 6), (4, 2), (11, 2)}
{(–4, 5), (–2, 9), (–1, 8), (4, 8), (11, 4)}
{(–4, 4), (–2, –1), (–1, 0), (4, 1), (11, 1)}

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