EXAMPLE 2

EXAMPLE 2 Making a Line Graph

EXAMPLE 2 Making a Line Graph

Population

EXAMPLE 2 Making a Line Graph

PopulationThe table below shows the population of Austin County in southeast Texas from 1920 to 1990. Make a line graph of the data.

EXAMPLE 2 Making a Line Graph

PopulationThe table below shows the population of Austin County in southeast Texas from 1920 to 1990. Make a line graph of the data.

EXAMPLE 2 Making a Line Graph

STEP 1Make a list of ordered pairs. Think of each column in the table as an ordered pair: (year, population)

EXAMPLE 2 Making a Line Graph

STEP 1Make a list of ordered pairs. Think of each column in the table as an ordered pair: (year, population)

(1920, 18,874), (1930, 18,860), (1940, 17,384), (1950, 14,663),

(1960, 13,777), (1970, 13,831), (1980, 17,726), (1990, 19,832)

EXAMPLE 2 Making a Line Graph

STEP 2Choose a scale that includes all the population values in your table.

EXAMPLE 2 Making a Line Graph

STEP 2Choose a scale that includes all the population values in your table.

STEP 3

EXAMPLE 2 Making a Line Graph

STEP 2Choose a scale that includes all the population values in your table.

STEP 3Graph each point.

EXAMPLE 2 Making a Line Graph

STEP 2Choose a scale that includes all the population values in your table.

STEP 3Graph each point.

STEP 4

EXAMPLE 2 Making a Line Graph

STEP 2Choose a scale that includes all the population values in your table.

STEP 3Graph each point.

STEP 4Draw line segments to connect the points.

GUIDED PRACTICE for Example 2

In Exercises 5 and 6, use the graph above.

In which year was Austin County’s population the greatest?

5.

ANSWER

GUIDED PRACTICE for Example 2

In Exercises 5 and 6, use the graph above.

In which year was Austin County’s population the greatest?

5.

1990

ANSWER

GUIDED PRACTICE for Example 2

In Exercises 5 and 6, use the graph above.

In which year was Austin County’s population the greatest?

5.

6. Over which decades did the population have its greatest increase? How can you tell from the graph?

1990

ANSWER

ANSWER

GUIDED PRACTICE for Example 2

In Exercises 5 and 6, use the graph above.

In which year was Austin County’s population the greatest?

5.

6. Over which decades did the population have its greatest increase? How can you tell from the graph?

1970 to 1980.The segment between 1970 and 1980 shows the steepest angle of incline.

1990

EXAMPLE 3 Comparing Graphs

Radio Stations

EXAMPLE 3

The two graphs below both show the number of AM radio stations in the United States. The first uses a full scale. The second uses a broken scale, deleting values between 0 and 4500. Compare the graphs.

Comparing Graphs

EXAMPLE 3 Comparing Graphs

EXAMPLE 3 Comparing Graphs

SOLUTION

EXAMPLE 3

Both graphs are accurate displays.

Comparing Graphs

SOLUTION

EXAMPLE 3

Both graphs are accurate displays.

The number of AM radio stations is declining. The full scale shows that the decline is very slow.

Comparing Graphs

SOLUTION

EXAMPLE 3

Both graphs are accurate displays.

The number of AM radio stations is declining. The full scale shows that the decline is very slow.

The broken scale makes the data easy to read, but makes the decline seem sharper than it is.

Comparing Graphs