This post was migrated to mathematics:
(Its revision history on CV can be seen here.)
At present I cannot identify any plausible reason why this one is off topic on our site. We have many hundreds, maybe even thousands of questions of precisely this kind; while it uses mathematics (solve an equation), it's directly answering a stats question (how do I find a confidence interval in this case?).
For consistency's sake, I'd like a clear explanation (preferably from each of the people who voted to migrate) of how we can determine that this question is off topic on our site -- what criteria can applied that would put this question over the line?
Getting the policy right here is a serious issue for us -- if we don't identify some criterion that leaves lots of apparently similar questions on topic while this one is not, then many, many questions will need to be closed or migrated.
It looks to me like some of us are in for a very large amount of extra work here (unless we're just going to choose to be deliberately inconsistent, I suppose), and I want to have some clear guidelines to use when doing all that extra work. Right now I have no idea how to conclude this one is off topic.
[If it is in fact in error, I think that those involved should be the ones doing the legwork in redressing the issue -- getting it migrated back. Right or wrong, there's work to be done here.]
I've sought similar criteria before here (and elsewhere) on a number of other (to me) questionable migrations -- it's not like closure where a mistake can be undone with a couple of clicks, we need to be clear about why we're doing it. An example of such an earlier question is here.
[I don't recall having been offered clear criteria on those occasions, though I recall one where at least one or two people offered a level of justification, which overall suggests that there's a problem with some of the voting on migration. Since a migration is hard to undo, we should be prepared to justify why it's off topic.]
Edit (to address an issue in a couple of comments): If a question is on-topic at the source site, the clearly established principle (on many meta.SE threads as well as advice in parts of the help or other documentation relating to migration) is that it shouldn't be migrated; the exception would be where the OP requests it and it's on topic at the destination (in effect, if a question is on topic, askers get to decide where they want their question). As far as I see it, in deciding whether migration is appropriate, that leaves only the question of whether it's on topic here. To me it clearly is, but there's clearly thought to be room for argument (as in the comments).