6.2.7 If (x1, . . ., xn) is a sample from a Beta(a, 1) distribution where a > 0 is unknown, then determine the MLE of a. you can express the pdf in a form that does not have gamma functions. (What is the right constant so it integrates to 1?) (b) Provide a statistic (reduced from the sample itself) that is sufficient for a. (c) What is the MLE for Var(Xi)? (d) Compute E(X) and use this to obtain a method of moments estimator for a