Basic Mathematics for College Students

Chapter 7 Summary and Review 623

The California row contains 4 complete symbols and almost all of

another. This means that there were , or 4,000 medical students,

plus approximately 900 more. In 2008, about 4,900 students were

enrolled in California medical schools.

4 1,000

In a circle graph,regions called sectors(they
look like slices of pizza) are used to show what
part of the whole each quantity represents.

CHECKING E-MAIL The circle

graph to the right shows the results of

a survey of adults who were asked

how many personal e-mail addresses

they regularly check. What percent of

the adults surveyed check 4 or more

e-mail addresses regularly?

We add the percent of the responses for 4 or 5 e-mail addresses and the

percent of the responses for 6 or more e-mail addresses:

5% + 5% = 10%

Thus, 10% of the adults surveyed check 4 or more e-mail addresses

regularly.

Use the survey results to predict the number of adults in a group of

5,000 that would check only one e-mail address regularly.

In the survey, 42% said they check only one e-mail address. We need to

find:

is of

x  42%  5,000 Translate.

Write 42% as a decimal.

Do the multiplication.

According to the survey, about 2,100 of the 5,000 adults would check

only one e-mail address regularly.

x2,100

x0.425,000

    

42% 5,000?

What

number

2 or 3

e-mail

addresses

48%

One

e-mail

address

42%

6 or more

5%

Source: Ipsos for Habeas

4 or 5

5%

A line graphis used to show how quantities
change with time. From such a graph, we can
determine when a quantity is increasing and
when it is decreasing.

SNOWBOARDING The line graph below shows the number of

people who participated in snowboarding in the United States for the

years 2000–2007.

2000

1.0

2.0

3.0

4.0

5.0

6.0

7.0

2001 2002 2003 2004

Year

2005 2006 2007

Millions

Number of people who participated

in snowboarding in the U.S.

Source: National Ski & Snowboard Retailers Association