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Median of three uniforms on (0,3) in the middle third

Question

Three independent random variables are each uniform on (0,3)(0,3). What is the probability that their median lies between 11 and 22?

Short answer

13/2713/27. Each variable falls in (0,1)(0,1), (1,2)(1,2) or (2,3)(2,3) with probability 1/31/3. The median lands in the middle third unless at least two fall in the same outer third: 1−2[3⋅227+127]=1−1427=13271-2\left[3\cdot\tfrac{2}{27}+\tfrac{1}{27}\right]=1-\tfrac{14}{27}=\tfrac{13}{27}.

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