I noticed on StackExchange that the percentage of answered questions for StackOverflow, SuperUser and ServerFault is at 83/82 percent for all three.
I wonder whether there is some explanation of that? This looks like it has some mathematical basis?
It's just the average amount of questions that get answered for which the OP comes back and selects an answer. The percentage doesn't happen to change much with a change of topic; I don't find anything too unusual with it.
It's like counting the number of smokers that are managers, programmers, construction workers and bankers, and coming to the conclusion that each group has between 23% and 25% of smokers. It doesn't seem something too implausible, does it?
There is no "mathematical basis" for it, it's just the way it is.