what is a whisker plot
A box and whisker plot is a way of summarizing a set of data measured on an interval scale. It is often used in explanatory data analysis. This type of graph is used to show the shape of the distribution, its central value, and its variability. In a box and whisker plot: 1  the ends of the box are the upper and lower quartiles, so the box spans the interquartile range. 2  the median is marked by a vertical line inside the box.  the whiskers are the two lines outside the box that extend to the highest and lowest observations.