Lesson 10-2 Pages 418-421

Making Circle Graphs

What you will learn!

How to construct and interpret circle graphs.

Circle graphCircle graph

What you really need to know!

A graph used to compare parts of a whole is called a circle graph. In a circle graph, the percents add up to 100. When percents are not given, you must first determine what part of the whole each item represents.

Example 1:

In a survey, a group of middle school students were asked to name their favorite sport. The results are shown in the table. Make a circle graph of the data.

SportSport PercentPercent

FootballFootball 30%30%

BasketballBasketball 25%25%

BaseballBaseball 22%22%

TennisTennis 8%8%

OtherOther 15%15%

SportSport PercentPercent Degrees of CircleDegrees of Circle

FootballFootball 30%30% 360 x .3 = 108360 x .3 = 108°°

BasketballBasketball 25%25% 360 x .25 = 90360 x .25 = 90°°

BaseballBaseball 22%22% 360 x .22 = 79.2360 x .22 = 79.2°°

TennisTennis 8%8% 360 x .08 = 28.8360 x .08 = 28.8°°

OtherOther 15%15% 360 x .15 = 54360 x .15 = 54°°

15% Other

30% Football25%

Basketball

22% Baseball

8% Tennis

Example 2:

Gina has the following types of movies in her DVD collection. Make a circle graph of the data.

Type of MovieType of Movie NumberNumberActionAction 2424

ComedyComedy 1515Science FictionScience Fiction 77

Type of MovieType of Movie NumberNumberActionAction 2424

ComedyComedy 1515Science FictionScience Fiction 77

PercentPercent52% (0.52)52% (0.52)33% (0.33)33% (0.33)15% (0.15)15% (0.15)

DegreesDegrees187187°°119119°°5454°°

52% Action

33% Comedy

15% Science Fiction

Example 3:

The circle graph shows the percent of voters in a town who are registered with a political party. Use the graph to describe the voters in this town.

Independent/Others

3%

Republicans42%

Democrats55%

More than half are Democrats and only

a very few are Independents.

Page 420

Guided Practice

#’s 3-6

Pages 418-419 with someone at home and study

examples!

Read:

Homework: Page 420-421

#’s 7, 8, 10-13

#’s 17-26 all

Lesson Check 10-2

Page

587

Lesson 10-2

Navy

Sky/L-Blue

Aqu

amar

ine

Other

55 mph

65 mph

70 mph 75 mph

Driving Alone

Carpool

Public Transit

Other

Driving Alone

Car

pool

Public Transit

Other

Mammals

Birds Reptiles

Amphibians

Northeast

Midwest

South West