help on proportions

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. 
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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.?? 
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The intersection of ResultSet and ProcSet are 80 genes.? 
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That means 40% of ProcSet are significant.?
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?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. 
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What I have:
n = 200 (ProcSet)
p = 0.4
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N = 1500? (ResultSet)
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N1 =10,000? 
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Pn = 0.15
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What kind of test will help me know that 0.4 is significant given 0.15. Any suggestions will greatly help me. 
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Thank you. 
Srini