A new medical screening test is used to detect a rare, non-life-threatening condition. If a person has this condition, the test always detects it. Approximately 0.2% of the population has the condition. Over many trials, the test returns a positive result 6% of the time. Julio takes the test and gets a positive result. To the nearest tenth of a percent, what is the probability that Julio actually has the condition?

Question

mathmate · Answer

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Since the person tests positive, the probability of him having the condition is no longer 0.2% out of 100%, but 0.2% out of 6%.
Can you find the value of the probability?