<p>It depends -- a lot of probability is very mathematical, and so MathOverflow may be a more appropriate place.  You'll simply get better answers there because each community has different interests and willingness to answer varies by the type of question.  On the other hand, probability is very much central in questions regarding data and may be entirely appropriate.  You may want to consult the questions tagged probability on this site and MathOverflow to get a sense of the difference:</p>

<ul>
<li><a href="https://stats.stackexchange.com/questions/tagged/probability">Statistical Analysis</a></li>
<li><a href="https://mathoverflow.net/questions/tagged/pr.probability">MathOverflow</a></li>
</ul>

<p>Note that a lot of probability questions are answered here.  Maybe you can suggest appropriate wording for the FAQ:</p>

<ul>
<li><a href="https://stats.meta.stackexchange.com/questions/6/what-should-our-faq-contain">What should our FAQ contain?</a></li>
</ul>

<p>Then the moderators or community can decide if it works well enough to modify the FAQ.</p>
