Colormetric method is used to test lake water for nitrates. If water specimens contain nitrates, a solution dropped into the water will cause the specimen to turn red 95% of the time. When used on water specimens without nitrates, the solution causes water to turn red 10% of the time. A past lab study indicates that nitrates are contained in 30% of the water specimens that are sent to the lab for testing. If a water specimen is randomly selected and turns red when tested, calculate the probability that it actually contains nitrates. Use a tree diagram.