Hi!

The task is to determine if estimate of the parameter is unbiased. In order to do that, i must find expected value of the parameter, given distribution of each observation which are iid.

I have come to this $\displaystyle E(\frac{1}{\sum_{i=1}^N X_i})$, where $\displaystyle EX_i$ is given. I think in general $\displaystyle E(\frac{1}{\sum_{i=1}^N X_i}) \neq \sum_{i=1}^N(\frac{1}{ E X_i})$.

So how can I calculate this expected value then?