A box and whisker plot is defined as a graphical method of displaying variation in a set of data.
The median value is displayed inside the "box." The maximum and minimum values are displayed with vertical lines ("whiskers") connecting the points to the center box.
The parts of a box-and-whisker plot are
Minimum value: The smallest value in the data set
Second quartile: The value below which the lower 25% of the data are contained
Median value: The middle number in a range of numbers
Third quartile: The value above which the upper 25% of the data are contained
Maximum value: The largest value in the data set
The "box" is the data between the second quartile and third quartile, which represents 50% of the data. In our problem, the second quartile is 20 and the third quatile is 76, therefore, the data between 20 and 76 represents 50% of the data.