Could someone please help me with this question? I'd greatly appreciate it. The freezing point of water varies directly with the salt content of the water. Fresh water (no salt content) freezes at a temperature of 0°C. Ocean water has a salt content of 3.5% and freezes at -2°C. Identify the independent and dependent variables. Explain your choices.​

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