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Suppose that X and Y are random samples of observations from a population with mean μ...

Suppose that X and Y are random samples of observations from a population with mean μ and variance σ2.

Consider the following two unbiased point estimators of μ.

A = (2/3)X + (1/3)Y B = (5/4)X - (1/4)Y

Find variance of A. Var(A) and Var(B)

Efficient and unbiased point estimator for μ is = ?

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