Box-and-Whisker Plots We are learning to…create and analyze Box-and-Whisker plots.

Box-and-Whisker Plot Vocabulary Median – The middle number of a set of data. Upper Quartile – The median of the data values that are greater than the median of the total data set. Lower Quartile – The median of the data values that are less than the median of the total data set. Maximum– The highest number in a set of data Minimum- The lowest number in a set of data Range- the difference between the minimum and maximum. Inter-Quartile Range – the difference between the upper and lower quartile of a set of data

Box-and-Whisker Plot Practice Make a box-and-whisker plot using the following set of data: 19, 18, 9, 4, 15 Step #1: Put the numbers in order from least to greatest: 4, 9, 15, 18, 19 Step #2: Find the median of your data. Step #3: Draw a number line. Step #4: Draw 2 dots- 1 dot above the minimum value of your data and 1 dot above the maximum value of your data. Step #5: Draw a vertical line at the median. Step #6: Find the median of the first half of the data and draw a vertical line. Step #7: Find the median of the second half of the data and draw a vertical line. Step # 8 Draw two horizontal lines to complete your box

Box-and-Whisker Plot Practice There are 12 people are in a Habanera Pepper eating contest who ate the following amount of peppers: 4, 4, 4, 9, 15, 2, 5, 0, 10, 12, 1, 18 Put the numbers in order from least to greatest: 0, 1, 2, 4, 4, 4, 5, 9, 10, 12, 15, 18 BELOW THE MEDIAN (4.5) ABOVE THE MEDIAN (13.5) Discussion Question: Why are all of the Boxes and Whiskers different sizes?

How to find the: Inter-Quartile Range Inter-Quartile Range – the difference between the upper and lower quartile of a set of data. Inter-Quartile Range = Upper Quartile – Lower Quartile Show where you could find the inter-quartile range on the box-and-whisker plot below: INTER-QUARTILE RANGE

Evaluation Questions

Colby graphed some data as shown in this box-and-whisker plot. Which statement is true about Colby’s data? The range of the data is 25. One-half of the data is below 65. The median of the data is 60. Three-fourths of the data is below 90. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

The inter-quartile range is 8 The upper quartile is -2. Which of the following is not true about the box-and-whisker plot shown below? The inter-quartile range is 8 The upper quartile is -2. The median of the data is 1. The lower extreme is -9. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

1. 2. 3. 4. 5.