The brange/b is the difference between the largest and smallest values in the data set.
The blower quartile/b ((Q1)) is the value which lies a quarter of the way in when values are arranged in ascending order in a data set.
It is the value equal to (\dfrac{n+1}{4}).
The bupper quartile/b ((Q3)) is the value which lies three quarters of the way in when values are arranged in ascending order in a data set.
It is the value equal to (\dfrac{3(n+1)}{4}).
The binter-quartile range/b ((IQR)) is equal to the difference between the upper and lower quartiles.
[b]uInter-quartile range[/u]/b
(IQR = Q3 - Q_1)