Yeah it's called guesstimating 
There's no way to objectively calculate the worth of an innocent person's life anyway, so you can't really put it into a formal equation. Sometimes you just have to make decisions based on incomplete information, I don't see what the problem is. It's not like I want to kill kids, but if I evaluated that there's a high enough chance that it could save a high enough number of lives, I'd pull the lever on that trolley problem 100%. What am I, a Kantian?