[Costanza]

As others have already said, there isn't an exact mathematical answer to this problem. The only way you could get one is if UTG flips over his cards before you have to make your decision.

The closest you can get to "an exact mathematical answer" is to decide what range of hands you think he would make this raise with and use something like PokerStove to calculate your chances of winning against this range of hands. You know how many chips you have if you fold. If you think you know what your chances of winning are you can calculate how many chips you'll have on average if you call [(chips left if you win)(probabilty that you'll win)+(chips left if you lose)(probability that you'll lose)].

However, it's a little more complicated than that. What you really want to know is not just how many chips you'll have, but how much tournament equity you'll have. This can be calculated with ICM (independent chip model) which, although slightly flawed, gives you an idea of how much money you'll win given your stack size in relation to the other stacks and the payout distribution of the tournament.

The easy way to figure all this out is to get eastbay's SNG Analyzer. You can search for it here on this forum. I think he also still has a classified ad for it on the site.