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In: Statistics and Probability

Suppose that the random variable Y1,...,Yn satisfy Yi = ?xi + ?i i=1,...,n. where the set...

Suppose that the random variable Y1,...,Yn satisfy Yi = ?xi + ?i i=1,...,n. where the set of xi are fixed constants and ?i are iid random variables following a normal distributions of mean zero and variance ?2.

?a (with a hat on it) = ?i=1nYi xi  /  ?i=1nx2i is unbiased estimator for ?.

The variance is  ?a (with a hat on it) = ?2/  ?i=1nx2i . What is the distribation of this variance?

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