The question requires me to approximate binomial distribution to get poisson distribution.
Show that N!/(N-n)!=N^n.
N!/n!(N-n)! p^n q^(N-n)=Binomial distribution
The Attempt at a Solution
I expanded N!/(N-n)! and got: (N-1)(N-2)(N-3)....(N-n+2)(N-n+1). This didn't help me in getting the required approximation. So, then I wrote it as follows:( N-(n-(n-1)) ) ( N-( n- (n-2) ) )...( N-(n-2) ) ( N-(n-1) ).
It seem to have further complicated the question.
A little help please.