how are tied answers decided?

There are millions tied up like that and there is a group called the "Tie Busters" who work through the categories casting a vote to break the tie.

You can do that just by always picking a Best Answer to your own question (get 3 points back) and then go through all of them and vote for those "in voting".

I did that some years ago and I am reasonably sure I have none, unless they are recent ones as I do that once a week. As you can see I have thousands of answers so I can assure you it will take a lot of time but overall worth the effort, and it increased my BA % by about 5%

Chetak

They stay tied until someone votes and breaks the tie. There are groups of YA users who go around voting on old questions to break the ties.

If a question goes to Tiebreaker because there is no majority vote for a best answer (or "No Best Answer") then it will stay that way indefinitely until a deciding vote is cast, which could be a very long time.

this is going to stay open for balloting till there's a winner, in spite of the undeniable fact that this would in no way take place and it would desire to stay completely tied. in case you haven't any longer already voted, vote on your very own answer as suitable answer, or get your associates to vote for you.