[R] help on proportions

[Srinivas Iyyer]

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