2. Lesson Menu Main Idea and New Vocabulary Example 1:Display Data in a Stem-and-Leaf Plot Example 2:Analyze Stem-and-Leaf Plots Example 3:Effect of Outliers

3. Main Idea/Vocabulary Display and analyze data in a stem-and-leaf plot. stem-and-leaf plot leaf stem outlier

4. Example 1 Display Data in a Stem-and-Leaf Plot SPORTS The table shows the number of home runs Cliff Floyd hit in the seasons from 1993 to 2008. Display the data in the table in a stem-and-leaf plot.

5. Example 1 Step 1 Choose the stems using digits in the tens place, 0, 1, and 2. The least value, 1, has 0 in the tens place. The greatest value, 34, has 3 in the tens place. Display Data in a Stem-and-Leaf Plot

6. Example 1 Step 2 List the stems from least to greatest in the Stem column. Write the leaves, the ones digits, to the right of the corresponding stems. Display Data in a Stem-and-Leaf Plot

7. Example 1 Step 3 Order the leaves and write a key that explains how to read the stems and leaves. Include a title. Display Data in a Stem-and-Leaf Plot

8. Example 1 Display Data in a Stem-and-Leaf Plot The ten digits of the data form the stem. The ones digits of the data form the leaves. Always write each leaf, even if it repeats. Include a key.

9. Example 1 Display Data in a Stem-and-Leaf Plot Answer:

10. Example 1 CYP TENNIS The table shows the number of service aces Joe hit in tennis matches each week of the tennis season. Display the data in the table in a stem-and-leaf plot. A. B. C. D.

11. Example 2 FOOTBALL The stem-and-leaf plot shows the number of points scored by the University of Florida football team in the 2007 season. Find the range, median, and mode of the data. Analyze Stem-and-Leaf Plots range: most points – least points = 59 – 17 or 42 median:middle value, 45 mode: most frequent value, 59

12. Example 2 Analyze Stem-and-Leaf Plots Answer:The range is 42, the median is 45, and the mode is 59.

13. Example 2 CYP A.range: 17; median: 15; mode: 21 B.range: 8; median: 15; mode: 21 C.range: 17; median: 5; mode: 1 D.range: 8; median: 5; mode: 1 VOLLEYBALL The stem-and-leaf plot shows the number of matches won over the last 10 seasons by a high school volleyball team. Find the range, median, and mode of the data.

14. Example 3 Effect of Outliers BASKETBALL The stem-and-leaf plot shows the number of points scored by a high school basketball player. Which measure of central tendency is most affected by the outlier?

15. Example 3 The modes, 15 and 31, are not affected by the inclusion of the outlier, 49. Calculate the mean and median, each without the outlier, 49. Then calculate them including the outlier and compare. Effect of Outliers

16. Example 3 20 without the outlier Effect of Outliers Answer: The mean increased by 21.9 – 19.7, or 2.2, while the median increased by 20 – 19 or 1. Since 2.2 > 1, the mean score is most affected. with the outlier

17. Example 3 CYP A.median B.mode C.mean D.The outlier does not affect any of the measures. BIRD-WATCHING The stem-and-leaf plot shows the number of birds in Lucy’s backyard over 8 days. Which measure of central tendency is most affected by the outlier?