Probability in tournaments

[act]

Lets say you are in a tournament with 5 players. Everybody is same skill level as yourself, and blinds are small.

You are in third and the chipcounts are:
1) 4000
2) 2500
3) 2000
4) 1500
5) 1000

Now Sklansky would argue that you chance of finishin first is 2000/10000 or 20%. My question is:
how would you estimate your probability of ending second? Or third? Fourth? Fifth (ok I can give you the last one if you give me 1-4 [img]/images/graemlins/grin.gif[/img]).

[img]/images/graemlins/confused.gif[/img]