Example 17-8. X1, X2, and X3 is a random sample of size 3 from a population with mean value u and variance o?. T1, T2, T3 are the estimators used to estimate mean value u, where T3 = (^X, + X2 + X3)/3. T = X1 + X2- X3, T2 = 2X1 + 3X3- 4X2 , and (i) Are T1 and T2 unbiased estimators ? (ii) Find the value of a such that Ta is unbiased estimator for u.
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