1. Splash Screen

2. Then/Now You have already found measures of central tendency. (Lesson 13–2) Find measures of variation. Display data in a box-and-whisker plot.

3. Vocabulary Measures of variation – used to describe the distribution of statistical data box-and-whisker plot – a diagram that divides a set of data into four parts using the median and quartiles box = the quartile values whiskers = extend to the extreme data points

4. Concept

5. Outliers = greater than or less than the IR 1.5

6. Example 3 Find Outliers NUTRITION Find any outliers in the data set. 2.5 3 3 4.5 5 5 6 8 14 lower quartilemedianupper quartile Step 1Place the numbers in order from least to greatest and find the median, lower quartile and upper quartile Median: 5 Lower quartile: Upper quartile:

7. Example 3 Find Outliers NUTRITION Find any outliers in the data set. Step 2Find the interquartile range. 7 – 3 = 4. Interquartile range = UQ – LQ = Step 3Multiply the interquartile range by 1.5. 1.5 ● 4 = 6 Step 4Subtract 6 from the lower quartile and add 6 to the upper quartile. 3 – 6 = –37 + 6 = 13 Answer: The only outlier is 14 because it is greater than 13.

8. Example 1 Draw a Box-and-Whisker Plot JOBS The projected number of employees in 2010 in the fastest-growing occupations is shown. Display the data in a box-and-whisker plot. Step 1Find the least and greatest number. Then draw a number line that covers the range of the data.

9. Example 1 Draw a Box-and-Whisker Plot Step 2Find the median, the extremes, and the upper and lower quartiles. Mark these points above the number line.

10. Example 1 Draw a Box-and-Whisker Plot Step 3Draw the box and the whiskers. Answer: