⚠️⚠️How do you solve a dilation?⚠️⚠️ I missed the day it was taught and now I’m confused

Here’s a math problem you can use as an example in the image above
also just in case: I know I can ask my teacher for help and they kinda did but I’m still lost

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