4. Suppose that 1:1. . .. ,m\" is a simple random sample from a Beta{1,3 + 1} distribution Iii-1:5} = (E + 1}(1 t)", :1: a: :1: 1. The Betafr, 3} distribution satises that E[X*] = 111:3\"? + g'fr + 3 + 5}}. {a} Show that J? is an unbiased estimator of 13"[9 + 2} {b} Obtain the information lower bound tor an estimator of 1,."(3 + 2}. {e} Doe; I? attain the inormation lower bound? Give reasons for your answer. You can get part marks tor indicating how you would address this question in principle. {d} What is the m estimator of -1f[' + 1)? The answer should be short but requires reasons. It' you don't see it, answer other questions and return to it