The box and whisker plot is a figure that displays the five-number summary of a set of data. This includes the minimum, the maximum, the upper quartile, the lower quartile, and the median.
From the data given, notice that the minimum value is 3 and the maximum value is 16.
Also, note that the numbers 9 and 10, fall in the middle. Hence, the median or the second quartile Q2 of the data is:
The first quartile or the lower quartile is the median of the lower half of the data in a set.
To find the first quartile (Q1), group the data into a lower half:
Notice that the median of the lower half is 7. Hence, the first quartile or the lower quartile is 7:
The upper quartile Q2 is the median of the upper half of the data.
The upper half of the data is:
Notice that the median of the upper half is 13.
It follows that:
