Four students plan to conduct an experiment with four conditions (a, b, c, and d) during one semester. each student will serve as an experimenter. the best way to control for the extraneous variable of having four experimenters test participants in the study is to

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