Boxplots and outliers

The points on the line represent the scores of 50 students in an examination. The points can be dragged along the line to investigate how the shape of the boxplot changes. Outliers are sometimes defined as points that lie more than 1.5 x the interquartile range either above the upper quartile or below the lower quartile. The boundaries for outliers are shown by the red dotted lines, and any outliers are shown in red.