Hi Guys, What is the distribution of N is this question? i would have assumed poisson, but the mean and var arent the same once we have computed them from the conditional formulae Thanks Molly
Hi Molly N is a Poisson RV but the parameter is treated as a random variable. So: N | mu = a ~ Poi(a) or N | mu ~ Poi(mu) The unconditional moments (eg E[N] = E[E[N| mu]] can be calculated using the formulae on page 16 of the Tables. Hope this helps Andy