Sometimes we have to estimate the interquartile range from a cumulative frequency diagram. It is acceptable when dealing with an even total cumulative frequency to use LQ = \(\frac{n}{4}\) ...

where matrix is any n ×m matrix. The GBXWHSKR module draws a box-and-whisker plot for univariate numeric data contained in the specified matrix. The box outlines the quartile range, and the minimum, ...