A really lame frat for stats majors, whose chant is “Chi-Square! Chi-Square! Cute Girls Beware!” Or, in real life, a statistic that shows how far the actual counts in certain data are from what we expect to happen. It applies to categorical data (think: survey results, like about how many people say they support the banning of dihydrogen monoxide, or other topics that you talk about with your friends at 3 AM).
Chi square stats can be used to help with anything from determining if your bag of M&Ms has more greens that it should or if the values on a possibly fake tax return are likely to be made up. Guess which of those calculations IRS agents are likely to do. Trick question! The answer is "both," but they only get paid to do it for tax stuff. The green M&Ms stuff happens in chat rooms on the weekends.
