Introduction to Interquartile range

Introduction to interquartile range for a given set of date:

The range is the smallest of all the measures of dispersion. It is defined as the difference between the two extreme observation of the distribution. In other words, range is the difference between the greatest ( maximum ) and the smallest (minimum) observation of the distribution.

Range = Xmax - Xmin

Where Xmax is the greatest observation and Xmin is the smallest observation of the variable values.

In case of the grouped frequency distribution or the continuous frequency distribution, range is defined as the difference between the upper limit of the higher class and the lower limit of the smallest class.

I hope the above explanation helped you...