It works like this:
A bounty is 1000 coins. If there is one person with one stake, he will get all the coins. If there are two people with one stake each, they will get 500 each. And so on. Bounty pool divided by total stakes gathered by participants times your stakes is how much coins you will get.
(pool / total stakes gathered by everyone) * your stakes = your coins
In the above example with 1000 coins and two people with 1 stake each:
(1000 / 2) * 1 = 500
Now I got the idea behind this. Thank you so much for this explained and well understandable answer. Now I got idea how much I will get from a pool of a special bounty campaign.