Holt CA Course 1 11-3Box-and-Whisker Plots Warm Up 1. Order the test scores from least to greatest: 89, 93, 79, 87, 91, 88, 92. 2. Find the median of the.

Holt CA Course 1

11-3 Box-and-Whisker Plots

Warm Up1. Order the test scores from least to greatest: 89, 93, 79, 87, 91, 88, 92.

2. Find the median of the test scores.

Find the difference.

79, 87, 88, 89, 91, 92, 93

89

16.1

166.9

0.8

3.4

3. 17 – 0.9 4. 8.4 – 7. 6

5. 9.1 – 5.7 6. 190.3 – 23.4

Holt CA Course 1

11-3 Box-and-Whisker Plots

7.SP.3Compare two numerical data

distributions.

Common Core State Standards Learning Objective

Holt CA Course 1

11-3 Box-and-Whisker Plots

Vocabulary

lower quartileupper quartilebox-and-whisker plotminimummaximum

Holt CA Course 1

11-3 Box-and-Whisker Plots

Litter Size 2 3 4 5 6

Number of Litters 1 6 8 11 1

The table below summarizes a cat breeder’s records for kitten litters born in a given year. You can divide the data into four equal part using quartiles.

Holt CA Course 1

11-3 Box-and-Whisker Plots

Kitten Data

2 3 3 3 3 3 3 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 5 5 5 6

Lower half Upper half

Lower quartile: 3 median of lower half

Upper quartile: 5 median of upper half

Median: 4

You know that the median of a data set divides the data into a lower half and an upper half. The median of the lower half is the lower quartile, and the median of the upper half is the upper quartile.

Holt CA Course 1

11-3 Box-and-Whisker Plots

Find the lower and upper quartiles for the data set.

Additional Example 1: Finding Quartiles

A. 15, 83, 75, 12, 19, 74, 21

12 15 19 21 74 75 83 Order the values.

lower quartile: 15

upper quartile: 75

Holt CA Course 1

11-3 Box-and-Whisker Plots

Find the lower and upper quartiles for the data set.

Additional Example 1: Finding Quartiles

B. 75, 61, 88, 79, 79, 99, 63, 77

61 63 75 77 79 79 88 99

lower quartile: = 6963 + 752

upper quartile: = 83.579 + 88

2

Order the values.

Holt CA Course 1

11-3 Box-and-Whisker Plots

Find the lower and upper quartiles for the data set.

Check It Out! Example 1

A. 25, 38, 66, 19, 91, 47, 13

13 19 25 38 47 66 91 Order the values.

lower quartile: 19

upper quartile: 66

Holt CA Course 1

11-3 Box-and-Whisker Plots

B. 45, 31, 59, 49, 49, 69, 33, 47

31 33 45 47 49 49 59 69 Order the values.

Find the lower and upper quartiles for the data set.

Check It Out! Example 1

lower quartile: = 3933 + 452

upper quartile: = 5449 + 59

2

Holt CA Course 1

11-3 Box-and-Whisker Plots

1 2 3 4 5 6 7 8 9

A box-and-whisker plot shows the distribution of data. The middle half of the data is represented by a “box” with a vertical line at the median. The lower fourth and upper fourth quarters are represented by “whiskers” that extend to the minimum (least) and maximum (greatest) values.

Lower quartile Upper quartileMedian

Holt CA Course 1

11-3 Box-and-Whisker Plots

Use the given data to make a box-and-whisker plot. 21, 25, 15, 13, 17, 19, 19, 21

Additional Example 2: Making a Box-and-Whisker Plot

Step 1. Order the data from least to greatest. Then find the minimum, lower quartile, median, upper quartile, and maximum.

13 15 17 19 19 21 21 25

minimum: 13 maximum: 25

lower quartile: = 16 15 + 17

2upper quartile: = 2121 + 21

2median: = 1919 + 19

2

Holt CA Course 1

11-3 Box-and-Whisker Plots

Use the given data to make a box-and-whisker plot.

12 14 16 18 20 22 24 26 28

Step 2. Draw a number line and plot a point above each value from Step 1.

13 15 17 19 19 21 21 25

Additional Example 2 Continued

Holt CA Course 1

11-3 Box-and-Whisker Plots

Use the given data to make a box-and-whisker plot.

12 14 16 18 20 22 24 26 28

Step 3. Draw the box and whiskers.

13 15 17 19 19 21 21 25

Additional Example 2 Continued

Holt CA Course 1

11-3 Box-and-Whisker Plots

23 24 26 29 31 31 33 35

Use the given data to make a box-and-whisker plot.

31, 23, 33, 35, 26, 24, 31, 29

Check It Out! Example 2

Step 1. Order the data from least to greatest. Then find the minimum, lower quartile, median, upper quartile, and maximum.

minimum: 23 maximum: 35

lower quartile: = 25 24 + 26

2upper quartile: = 3231 + 33

2

median: = 3029 + 31

2

Holt CA Course 1

11-3 Box-and-Whisker Plots

Use the given data to make a box-and-whisker plot.

22 24 26 28 30 32 34 36 38

Step 2. Draw a number line and plot a point above each value.

23 24 26 29 31 31 33 35

Check It Out! Example 2 Continued

Holt CA Course 1

11-3 Box-and-Whisker Plots

Step 2. Draw a number line and plot a point above each value.

Use the given data to make a box-and-whisker plot.

22 24 26 28 30 32 34 36 38

Step 3. Draw the box and whiskers.

23 24 26 29 31 31 33 35

Check It Out! Example 2 Continued

Holt CA Course 1

11-3 Box-and-Whisker PlotsCheck It Out! Example 3

Quarter 1 2 3 4

Oakland 3 0 6 12

Tampa Bay 3 17 14 14

These box-and-whisker plots compare the points per quarter at Super Bowl XXXVII.

Oakland

0 3 6 9 12 15 18

Tampa Bay

0 3 6 9 12 15 18

Holt CA Course 1

11-3 Box-and-Whisker Plots

A. Compare the medians.

Check It Out! Example 3A

The median for Tampa Bay is significantly greater than Oakland’s.

Oakland

0 3 6 9 12 15 18

Tampa Bay

0 3 6 9 12 15 18

Holt CA Course 1

11-3 Box-and-Whisker Plots

Lesson Quiz: Part I

Find the lower and upper quartiles for each

data set.

1. 48, 52, 68, 32, 53, 47, 51

2. 3, 18, 11, 2, 7, 5, 9, 6, 13, 1, 17, 8, 0

lower = 2.5; upper = 12

lower = 47; upper = 53

Holt CA Course 1

11-3 Box-and-Whisker Plots

Lesson Quiz: Part II

Use the following data for problems 3 and 4.

91, 87, 98, 93, 89, 78, 94

3. Make a box-and-whisker plot.

4. What is the median of the data?

91

78 87 91 94 98

Holt CA Course 1

11-3 Box-and-Whisker Plots

Checking for Understanding

Box and Whisker Plots

Holt CA Course 1

11-3 Box-and-Whisker Plots

Classwork & Homework

Lesson 11-3 Practice B

Lesson 11-3 Problem Solving