# [R] help on proportions

Ista Zahn istazahn at gmail.com
Fri Feb 1 13:26:32 CET 2013

```Hi Srini,

This is a statistics question, not a question about R, so this may not
be the best place to ask. Try posting at
http://stats.stackexchange.com/ or another statistics help list.

Best,
Ista

On Thu, Jan 31, 2013 at 11:11 PM, Srinivas Iyyer
<srini_iyyer_bio at yahoo.com> wrote:
> Hi:
> Apologies for asking the following question. As this may sound very basic and stupid for this forum , I honestly do not know how to solve it and I do not have a teacher who can help me understand.
>
> I have list of genes (200) that are involved in a particular process and I call this as a ProcSet.   From an independent experiment I found that out of 10,000 genes, 1500 are significant and I call these1500 genes as ResultSet.
>
> The intersection of ResultSet and ProcSet are 80 genes.
>
> That means 40% of ProcSet are significant.
>
>  How do I calculate that 40% is significant and more than I expect by chance given ResultSet and 10,000 genes I evaluated in the experiment.
>
> What I have:
> n = 200 (ProcSet)
> p = 0.4
>
> N = 1500  (ResultSet)
>
> N1 =10,000
>
> Pn = 0.15
>
> What kind of test will help me know that 0.4 is significant given 0.15. Any suggestions will greatly help me.
>
> Thank you.
> Srini
>
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```