Question 5. Suppose that Y1, Y5}, - - - , Y\" is an independent random sample from a normal distribution with mean a and variance 02. a. What is the expected value of Y, E(Y). b. Find 0011(Y1, Yg). Remember the formula for 0011(1'1, Y2) = E(Y1Y2) E(Y1)E(Y2). c. Show that %(Y1 Y2) is an unbiased estimator of a2