1. EXAMPLE 1 Making a Box-and-Whisker Plot Bridges The lengths, in meters, of the world’s ten longest suspension bridges are listed below. How can you display these data to show how the lengths are distributed? 1280 1490 1991 1377 1298 1210 1624 1158 1385 1410

2. EXAMPLE 1 Making a Box-and-Whisker Plot Display the bridge lengths above in a box-and-whisker plot. STEP 1 Order the data to find the median, the quartiles, and the extremes.

3. EXAMPLE 1 Making a Box-and-Whisker Plot STEP 2 Plot these values below a number line.

4. EXAMPLE 2 Interpreting Box-and-Whisker Plots You are testing whether a fertilizer helps tomato plants grow. You divide the plants into two equal groups, and give fertilizer to the plants in Group 2, but not to Group 1. The box-and-whisker plots show how much the plants grew, in centimeters, for each group of plants after two weeks. Food Science

5. EXAMPLE 2 Interpreting Box-and-Whisker Plots About what fraction of the unfertilized plants grew as much as any of the fertilized plants? a.a. About what fraction of the fertilized plants grew 4 to 8 centimeters? b.b. SOLUTION The right whisker for Group 1 overlaps the left whisker for Group 2. So about one quarter of the unfertilized plants grew as much as any of the fertilized plants. a.a. b.b.The large box in the plot for Group 2 ranges from 4 to 8, so about one half of the fertilized plants grew 4 to 8 centimeters.

6. GUIDED PRACTICE Exercising Over a period of ten days, Ming exercised for 34, 27, 26, 15, 24, 21, 30, 23, 24, and 35 minutes. Chantelle exercised for 26, 33, 36, 21, 41, 36, 29, 25, 34, and 35 minutes. Make a box-and-whisker plot of the data for each person. 1.1. for Examples 1, 2 and 3

7. GUIDED PRACTICE for Examples 1, 2 and 3 Who usually exercised longer? Explain. 2. Chantelle. Sample answer: The median workout time for Chantelle is longer than the third quartile time for Ming, and almost as long as the upper extreme for Ming. ANSWER

8. GUIDED PRACTICE 3. About how often did each person exercise for 25 –35 minutes? for Examples 1, 2 and 3 ANSWER about half the time for each