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Question
Let X be a random variable and Y = 2X + 1. What is the variance of Y if variance of X is 5?
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Solution
Var(X) = 5
Var(Y) = var(2x + 1) .......{∴ v(ax + b) = a2v(x)}
= (2)2var(X)
= 4(5)
Var() = 20
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