I've been struggling with this for the last couple of days. I would appreciate any illumination.
Let and be independent random variables where and with
Show that the conditional pdf of given is binomial with parameters and .
For notation I say N is the random variable taking a value N =n.
So then as I see it,
Which I reckon simplifies to
Which seems plausible, but I can't massage it into a binomial with parameters and
Thanks in advance for any light anyone can throw on this. MD