Five-Minute Check (over Lesson 8–5)

Main Idea and Vocabulary

Example 1:Use a Line Graph to Predict

Example 2:Use a Line Graph to Predict

Concept Summary: Types of Relationships

Example 3:Use a Scatter Plot to Predict

• line graph – useful in predicting future events because they show relationships or trends over time.

• scatter plot – displays 2 sets of data on the same graph (also useful because they show trends in data)

• Analyze line graphs and scatter plots to make predictions and conclusions (2.6.8C)(M7.E.4.1).

Use a Line Graph to Predict

TYPING The line graph shows the time that it has taken Enrique to type a class paper so far. The paper is 600 words long. Use the graph to predict the total time it will take him to type the paper.

Continue the graph with a dotted line in the same direction until you align vertically with 600.

Graph a point. Find the value in minutes that corresponds with the point.

Use a Line Graph to Predict

Answer: It will take Enrique about 14 minutes to type his 600-word paper.

1. A

2. B

3. C

4. D0% 0%0%0%

A. 450 miles

B. 600 miles

C. 700 miles

D. 775 miles

TRAVEL During a recent road trip, Helen kept track of the number of miles traveled after each hour of travel time was completed. Use the line graph to predict how far Helen will travel in 12 hours of travel time.

Use a Line Graph to Predict

TESTS The line graph shows the math test scores of a middle-school student for five chapters. If the trend continues, what do you think her score will be on the next math test?

Answer: If the trend continues, Susan’s score on the next test should be about 86%.

1. A

2. B

3. C

4. D

A B C D

0% 0%0%0%

A. about 150

B. about 225

C. about 260

D. about 300

CUSTOMERS The line graph shows the number of customers making purchases at a clothing store for six months. If the trend continues, what do you think will be the number of customers making purchases in the next month?

Use a Scatter Plot to Predict

POLLUTION The scatter plot shows the number of days that a city failed to meet air quality standards from 2000 to 2008. Use it to predict the number of days of bad air quality in 2014.

Answer: By looking at the pattern in the graph, we can predict that the number of days of bad air quality in 2014 will be about 48 days.

1. A

2. B

3. C

4. D

0% 0%0%0%

A. 10 mpg

B. 14 mpg

C. 20 mpg

D. 23 mpg

GAS MILEAGE The scatter plot shows the gas mileage based on the weight of a car. Use it to predict the gas mileage for a car weighing 5,500 pounds.

1. A

2. B

3. C

4. D0% 0%0%0%

A. population is increasing

B. population is decreasing

C. population is constant throughout

D. population is increasing and decreasing

The table shows the population for the town of Cedar Creek from 1990 to 2001. What trend can be observed about the population of Cedar Creek?

REVIEW

End of the Lesson

Five-Minute Check (over Lesson 8–5)

Image Bank

Math Tools

Line Plots