1. Box and Whisker Plots

2. Vocabulary To make a box and whisker plot, we break the data in quartiles. The ________________ _________________ is the median of the lower half of the data and the ________________ _________________ is the median of the upper half of the data. The _______________ _________________ _______________ is the difference between these two values.

3. Number of People in Household The numbers below represent the shoe sizes for a class of 7 th grade students. 8, 11.5, 6, 9, 10, 5.5, 7.5, 10.5, 8.5, 4.5, 11, 9, 9.5, 7, 7, 8.5, 7.5, 9, 9

4. Making a Box-and-Whisker Plot To create your own box-and-whisker plot, you must first find the following values. Lowest Value Lower Quartile Median Upper Quartile Highest Value 4.5, 5.5, 6, 7, 7, 7.5, 7.5, 8, 8.5, 8.5, 9, 9, 9, 9, 9.5, 10, 10.5, 11, 11.5 4.5 11.5 8.5 7 9.5 These numbers are usually called a “five number summary” for a set of data

5. Making a Box-and-Whisker Plot Lowest Value 4.5 Lower Quartile 7 Median 8.5 Upper Quartile 9.5 Highest Value 11.5 1. Plot the five values on an appropriate number line. 2. Connect the minimum and lower quartile with a line (called a whisker). 3. Connect the maximum and upper quartiles with another whisker. 4. Draw a box between the lower and upper quartiles, splitting the box at the median. 3 4 5 6 7 8 9 10 11 12 13