Box-and-Whisker Plots 1-6 Box-and-Whisker Plots Warm Up Problem of the Day Lesson Presentation Course 2

Box-and-Whisker Plots Course 2 1-6 Box-and-Whisker Plots Warm Up Use the data below for Questions 1-4. 14, 25, 37, 53, 26, 12, 70, 31 1. What is the mean? 2. What is the median? 3. What is the mode? 4. What is the range? 33.5 28.5 none 58

Box-and-Whisker Plots Course 2 1-6 Box-and-Whisker Plots Problem of the Day If the sixth-graders checked out 160 books, how many does each symbol in this pictograph represent?             Library Books Checked Out Sixth Grade Seventh Grade Eighth Grade 32 books

Box-and-Whisker Plots Course 2 1-6 Box-and-Whisker Plots Learn to display and analyze data in box-and-whisker plots.

Box-and-Whisker Plots Course 2 1-6 Box-and-Whisker Plots Vocabulary box-and-whisker plot first quartile second quartile third quartile lower extreme upper extreme

Box-and-Whisker Plots Course 2 1-6 Box-and-Whisker Plots The table shows the stopping distances of different vehicles from 60 mi/h. A 120 B 158 C 142 D 131 E 128 F 167 G 136 Vehicle Stopping Distance (ft) To show the distribution of the data, you can use a box-and-whisker plot.

Box-and-Whisker Plots Course 2 1-6 Box-and-Whisker Plots To make a box-and-whisker plot for a set of data, you need to divide the data into four equal parts using quartiles. The following box-and-whisker plot shows the distribution of the vehicles’ stopping distances.

Box-and-Whisker Plots Course 2 1-6 Box-and-Whisker Plots first quartile, the median of the lower half of the data set third quartile, the median of the upper half of the data set lower extreme, or minimum value upper extreme, or maximum value second quartile, the median of the data set 110 120 130 140 150 160 170 180

Box-and-Whisker Plots Course 2 1-6 Box-and-Whisker Plots Additional Example 1: Reading a Box-and-Whisker Plot Use the box-and-whisker plot of students enrolled in craft classes to answer each question. 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 A. What is the largest class size? The largest data value is represented by the upper extreme on the box-and whisker plot. This value is 25. B. What is the range of the class sizes? The range is the difference between the lower extreme and the upper extreme : 25 – 10 = 15. C. About what fraction of the values are greater than 20? One of the four parts of the box-and-whisker plot falls above 20. This means about one-fourth of the values are greater than 20.

Box-and-Whisker Plots Course 2 1-6 Box-and-Whisker Plots Try This: Example 1 Use the box-and-whisker plot of the amount of money spent on a pair of shoes to answer each question. 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 A. What was the highest amount of money spent on a pair of shoes? 41 B. What is the range of shoe prices? The range is the difference between the lower extreme and the upper extreme : 41 – 27 = 14. 1 2 C. What fraction of shoes cost more than $35?

Box-and-Whisker Plots Course 2 1-6 Box-and-Whisker Plots Additional Example 2: Making a Box-and-Whisker Plot Use the data to make a box-and-whisker plot. 73 67 75 81 67 75 85 69 Step 1: Find the lower and upper extremes, the median, and the first and third quartiles. Order the data from least to greatest. 67 67 69 73 75 75 81 85 Find the lower and upper extremes. 67 69 73 75 81 85 67 69 73 75 81 85 + Find the median. 2 =74

Box-and-Whisker Plots Course 2 1-6 Box-and-Whisker Plots Additional Example 2 Continued Find the first and third quartiles. 67 69 73 75 81 85 67 + 69 first quartile = = 68 2 75 + 81 third quartile = = 78 2

Box-and-Whisker Plots Course 2 1-6 Box-and-Whisker Plots Additional Example 2 Continued Step 2: Draw a number line. Above the number line, plot points representing the lower and upper extremes, the median, and the first and third quartiles. Step 3: Draw a box through the first and third quartiles. Inside the box, draw a vertical line through the median. Then draw lines from the first and third quartiles to the extremes. These lines are called whiskers. 64 66 68 70 72 74 76 78 80 82 84 86

Box-and-Whisker Plots Course 2 1-6 Box-and-Whisker Plots Try This: Example 2 Use the data to make a box-and-whisker plot. 42 22 31 27 24 38 35 Step 1: Find the lower and upper extremes, the median, and the first and third quartiles. Order the data from least to greatest. 22 24 27 31 35 38 42 Find the lower and upper extremes. 22 24 27 31 35 38 42 22 24 27 31 35 38 42 Find the median. Find the first and third quartiles. 22 24 27 31 35 38 42

Box-and-Whisker Plots Course 2 1-6 Box-and-Whisker Plots Try This: Example 2 Continued Step 2: Draw a number line. Above the number line, plot points representing the lower and upper extremes, the median, and the first and third quartiles. Step 3: Draw a box through the first and third quartiles. Inside the box, draw a vertical line through the median. Then draw lines from the first and third quartiles to the extremes. These lines are called whiskers. 20 22 24 26 28 30 32 34 36 38 40 42

Box-and-Whisker Plots Course 2 1-6 Box-and-Whisker Plots Lesson Quiz Use the data for Questions 1-3. 24, 20, 18, 25, 22, 32, 30, 29, 35, 30, 28, 24, 38 1. What is the range? 2. What is the 3rd quartile? 3. Create a box-and-whisker plot for the data. 20 31 18 20 22 24 26 28 30 32 34 36 38 40