I am trying to find the variance of $\frac{1}{x bar}$ given a Poisson random variable.
Now I have no idea as to how I can manipulate the expectation in regard to this finite sum, I am guessing i have to find $E(\frac{n}{\sum{xi^n}})^2-(E\frac{n}{\sum{xi^n}})^2$
Now I can take out $n$ squared from both expectations and factor it out, but I am struggling to conceptualize the expectation of the reciprocal.