29. Suppose {X1, X2,..., X16} is a random sample coming from Gamma(a = 4, β = 2} distribution.
Consider the following estimator for the population mean μ:
$$\hat{\theta} = 3\overline{X} - 4X_2 + 2X_3$$
(a) Show that $\hat{\theta}$ is an unbiased estimator for μ.
(b) Calculate the variance of $\hat{\theta}$, that is V($\hat{\theta}$).
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