7th Grade Math

Lesson 2B Measures of Variation 507

= Step-by-Step Solutions begin on page R1.

Extra Practice begins on page EP2.

Example 1 Draw a box-and-whisker plot for each set of data.

33 {65, 92, 74, 61, 55, 35, 88, 99, 97, 100, 96}

4. {26, 22, 31, 36, 22, 27, 15, 36, 32, 29, 30}


5. Height of Waves (in.)
   80 51 77
   72 55 65
   42 78 67
   40 81 68
   63 73 59
   6. Cost of MP3 Players ($)
   95 55
   105 100
   85 158
   122 174
   165 162

Examples 2 and 3 7. GEOGRAPHY The table shows the length of Length of Coastline (mi)

28 130

580 127

100 301

228 40

31 187

192 112

13

coastline for the 13 states along the Atlantic

Coast.

a. Make a box-and-whisker plot of the data.

b. What percent of the coastline states have

coastlines greater than 210 miles?

c. Half of the states have a coastline less than

how many miles?

d. Write a sentence describing what the length of the box-and-whisker

plot tells about the number of miles of coastline for states along the

Atlantic coast.

8. TESTS Use the box-and-whisker plot. It summarizes math test scores.

60626466687072747678808284868890929496 98 100

.BUI
5FTU
4DPSFT

a. What was the greatest test score?

b. Explain why the median is not in the middle of the box.

c. What percent of the scores were between 71 and 96?

d. Half of the scores were higher than what score?

Example 4 9. NUTRITION The amount of Calories for certain fruits and vegetables

is displayed. How do the Calories of fruits compare to vegetables?

0 50 100 150 200 250 300 350 400 450

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PG
$BMPSJFT

Fruits

Vegetables

Real-World Link

The total lengths

of U.S. coastlines

are shown below.

Atlantic Coast:

2,069 mi

Gulf Coast:

1,631 mi

Pacific Coast:

7,623 mi

Arctic Coast:

1,060 mi

RR

T

498_509_C09_L2_895130.indd 507 1/11/10 9:34 AM