Asking because I can’t find anywhere else on here

Which is the equation of a line perpendicular to the line with the equation 3x+4y=8

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

Which of the following circles have their centers in the third quadrant? check all that apply.