Final answer:
The mean of a random sample of size n is a minimum variance unbiased estimator of the parameter of a Poisson population because it satisfies the Cramer-Rao bound.
Step-by-step explanation:
The mean of a random sample of size n is a minimum variance unbiased estimator of the parameter of a Poisson population because it satisfies the Cramer-Rao bound.
To show this, we need to verify two conditions:
- The estimator is unbiased, which means that its expected value is equal to the true value of the parameter.
- The estimator's variance is equal to, or lower than, the lower bound given by the Cramer-Rao inequality.
For the mean of a random sample of size n, both conditions are satisfied.
Thus, the mean of a random sample of size n is a minimum variance unbiased estimator of the parameter of a Poisson population.