Asample of 20 international students attending an urban u. s. university found that the average amount budgeted for expenses per month was $1,612.50 with a standard deviation of $1,179.64. find a 95% confidence interval for the mean monthly expense budget of the population of international students.

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