Procedure for Constructing a boxplot
1. find the 5-number summary consisting of the minimum value, Q1, the median, Q3, and the maximum value.
2. Construct a scale with value that included the minimum and maximum data value
3. Construct a box (rectangle) extending from Q1 to Q3, and drawn a line in the box at the median value
4. Draw lines extending outward from the box to the minimum and maximum data values.