Well, if you wanted to be a real geek about it, given n attempts, your chances of a single success are 1 - (.95 ^ n)... but I'd also like to think that an entrepreneurial endeavor is not pure chance.
> I'd also like to think that an entrepreneurial endeavor is not pure chance.
Agreed, I don't think you'll ever succeed in your business attempts if you're not providing something new, original or just not established in the area. You'll make a killing opening a coffee shop in a moderate sized town - as long as there's not 3 Starbucks already there.
There's a lot to business beyond the idea, hence it's important to be a businessman once you've succeeded your entrepreneurial dream of getting a company started. You don't want your company to fail just because you fucked up and didn't file your taxes.