Three-person jury with a coin-flipping member
Question
Panel A has three members deciding by majority vote: two of them are each independently right with probability , while the third decides every case by tossing a fair coin. Panel B is one person who is right with probability . Which panel is more likely to reach the correct verdict?
Short answer
Neither — both are correct with probability . Panel A is right when the two serious members both are right (), or when they split () and the coin sides with the right one (half the time). That totals .
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Open the worked solutionLessons behind this question
- Sample Spaces, Events, and the Probability Axioms
- Independence
- Conditional Probability, Total Probability, and Bayes' Rule
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