Let X1, X2, . . . , X15 be a random sample from a Poisson distribution with mean k = 2?.
(a) Give an unbiased estimator for the parameter ?.
(b) An observed sample yields the following observations:
2 4 2 1 1 3 2 3 0 2 3 1 2 1 2
Give an unbiased estimate for ?
(c) Now suppose one decides to use only the last observation of a sample to estimate ?, that is, ?