Talk:Poisson limit theorem

Example review

It's been a little hard for me to understand why this example is an application of the theorem, so I thought I could suggest an extra sentence explaining a intermediate step of reasoning for the not-so-much-into-the-field people like me. Something like:

" Suppose that in an interval [0, 1000], 500 points are placed randomly. Now what is the number $k$ of points that will be placed in [0, 10]?

Intuitively, it will be most likely $k=5$, but other amounts are possible too, so the number $k$ should be instead a distribution. More correctly phrased, the probabilistically precise way of describing the number of points in the sub-interval would be to describe it as a binomial distribution $p_{n}(k)$. "

As I'm not sure whether it is worth to include such an impreciseness, I'm writing this in the talk page, asking for approval/rejection. But I think the implicit idea (expressed like this or in a better way) would be indeed useful.

jmmut 131.111.184.26 (talk) 17:38, 1 October 2015 (UTC)

Possible typo in proof

The proof's first equation is

${\begin{aligned}{n \choose k}p^{k}(1-p)^{n-k}&\simeq \lim _{n\to \infty }{\frac {n(n-1)(n-2)\dots (n-k+1)}{k!}}\left({\frac {\lambda }{n}}\right)^{k}\left(1-{\frac {\lambda }{n}}\right)^{n-k}\\&=\lim _{n\to \infty }{\frac {n^{k}+O\left(n^{k-1}\right)}{k!}}{\frac {\lambda ^{k}}{n^{k}}}\left(1-{\frac {\lambda }{n}}\right)^{n-k}\\&=\lim _{n\to \infty }{\frac {\lambda ^{k}}{k!}}\left(1-{\frac {\lambda }{n}}\right)^{n-k}\end{aligned}}$.

but it should be:

${\begin{aligned}\lim _{n\to \infty }{n \choose k}p^{k}(1-p)^{n-k}&=\lim _{n\to \infty }{\frac {n(n-1)(n-2)\dots (n-k+1)}{k!}}\left({\frac {\lambda }{n}}\right)^{k}\left(1-{\frac {\lambda }{n}}\right)^{n-k}\\&\simeq \lim _{n\to \infty }{\frac {n^{k}+O\left(n^{k-1}\right)}{k!}}{\frac {\lambda ^{k}}{n^{k}}}\left(1-{\frac {\lambda }{n}}\right)^{n-k}\\&=\lim _{n\to \infty }{\frac {\lambda ^{k}}{k!}}\left(1-{\frac {\lambda }{n}}\right)^{n-k}\end{aligned}}$.

--Corrado Mencar (talk) 14:11, 28 April 2020 (UTC)