This has been covered on meta.stackoverflow.com (unsurprisingly, since programming languages/libraries change so often).
Answers:
If you have the power, edit the existing answer and update it. If you do not have edit privilege, write a new one and add a comment to the existing one, pointing to yours. Ask others to merge them.
Questions:
Edit, if you can. If not, ask your own, link to the other question, explain why you ask again and ask a moderator, if he can merge the questions.
That said, I think most statistics questions are too ephemeral to really work here; and those that aren't (e.g. "Who has the most receiving touchdowns in NFL history?") are usually easily looked up, so I don't know that they're worth hosting either.