Theoretically, you could make one of those calculations like the one that says that a 50% chance at 2 million dollars is equal to a sure million dollars. To real-world proof it though, you'd have to factor in risk aversion.

That's called an expected value calculation:

http://en.wikipedia.org/wiki/Expected_value

I'm only pointing it out because I also want to note that it's a great way to determine if the contestants on Deal or No Deal are being boneheads.... ;-)