7th Grade Math

Chapter Study Guide and Review 549

More Statistical Displays

PSI: Use a Graph (Lesson 4A)

27. HOCKEY The graph shows the number
    of points scored in the first twelve
    hockey games. What is the average
    number of points scored so far this
    season?

Number of Points

Scored

3

2

4

1

0 123456789101112

5

Game

Hockey

EXAMPLE 7 Use the graph to find

the average test score.

Test Score

100

0 0.5 1 1.5 2

90

80

70

Hours Studied

Test Preparation

Add the test scores: 73 + 83 + 79 + 91 +

88 + 84 + 96 + 93 or 687

Divide: _^687

8

or 85.9

So, the average test score was 85.9.

Scatter Plots and Lines of Best Fit (Lesson 4B)

28. SPORTS Use the graph to describe the
    relationship between hours practiced and
    number of wins.

Hours Practiced

1.5

1

2

0.5

0 12345678910

2.5

3

3.5

Wins

Sports Practice

EXAMPLE 8 Use the scatter plot to

describe the relationship between the

flower height and water received.

Flower Height (in.)

1.5

1

2

0.5

0 2468101214161820

2.5

3

Water (mL)

Flowers

The graph shows no obvious patterns. So,

there is no relationship.

Select an Appropriate Display (Lesson 4C)

29. CALORIES Select an appropriate display
    to show individual students’ Calorie
    intake for lunch in numerical order.


30. SLEEP Is a circle graph an appropriate
    display to represent the number of calls
    made each day? Explain.

EXAMPLE 9 Select an appropriate

display for the number of Olympic

sprinters compared to the total number of

athletes. Explain.

A circle graph would be appropriate because

you are comparing a part to the whole.

Lesson 4

546_550_C09_SGR_895130.indd 549 1/11/10 9:47 AM