Function Interquartile-Range
(
interquartile-range &rest < args > )
INTERQUARTILE-RANGE (DATA)
The interquartile range is similar to the variance of a sample because both
are statistics that measure out ``spread out'' a sample is. The interquartile
range is the difference between the 3/4 quantile (the upper quartile) and the
1/4 quantile (the lower quartile).