Hi

I've this question:

X1,...,Xn it's a sample from a binomial distribution b(n,a). Find the maximum likelihood estimator of a and the expected value of the estimator.

I can find the MLE

Ignoring the binomial coefficient i have

I take logs and differentiate to obtain:

Upon equating to zero and solving i obtain that:

Now i must find the expected value of a but I'm very confused on how to do this. Any hint?

Thanks