Thanks, with a follow up question;
The wiki page on this is confusing me, to find the expectation;
do I differentiate and put n=1?
and if so is it the same approach for variance?
Thanks, with a follow up question;
The wiki page on this is confusing me, to find the expectation, do I differenttiate and put n=1? and if so is it the same approach for Variance?
If f is the generating function of a random variable X, then :
(like you said)
and , by linearity of the expectation.
This implies :