Variance of a normal with random mean and scale
Question
Let and be independent random variables. Conditional on and , the pair is bivariate normal with both means equal to , both variances equal to , and correlation , where is a fixed constant. Find .
Short answer
. By the law of total variance, . For these are and ; plays no role.
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Open the worked solutionLessons behind this question
- Expectation, Mean, and Variance
- Conditional Probability, Total Probability, and Bayes' Rule
- Worked Examples — Probability Trees, Monty Hall, and Bayesian Updating
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