Suppose you flip a coin 100 times, and it turns up heads 70 times.  Is
the coin fair?

Suppose you roll a die 100 times, and it shows 30 sixes.  Is the die
loaded?

In statistics, the chi-square test calculates "how random" a series of
numbers is.  But it doesn't simply say "yes" or "no".  Instead, it gives
you a confidence interval, which sets upper and lower bounds on the
likelihood that the variation in your data is due to chance.  See the
examples below.

There's just one function in this module: chisquare().  Instead of
returning the bounds on the confidence interval in a tidy little
two-element array, it returns an English string.  This was a deliberate
design choice---many people misinterpret chi-square results, and the
string helps clarify the meaning.

-Anton
<tobez@FreeBSD.org>