2. Main Idea and New Vocabulary Concept Summary: Types of Relationships
Example 1: Identify a Relationship
Example 2: Use a Line Graph to Predict
Example 3: Use a Scatter Plot to Predict
Lesson Menu

3. Analyze line graphs and scatter plots to make predictions and conclusions.
line of best fit
Main Idea/Vocabulary

4. Key Concept

5. Identify a Relationship
TEST Explain whether the scatter plot of the data for study time and test scores shows a positive, negative, or no relationship.
Answer: As the minutes spent studying increase, the test scores increase. Therefore, the scatter plot shows a positive relationship.
Example 1

6. EXERCISE Explain whether the scatter plot of the data for minutes of exercise and Calories burned shows a positive, negative, or no relationship.
A. positive
B. negative
C. no relationship
Example 1 CYP

7. Use a Line Graph to Predict
COUNTY FAIR The line graph shows the annual attendance at a county fair over the last 10 years. If the trend continues, how many people will attend the fair in 2014?
Draw the line that is close to most of the data points. If the trend continues, the attendance in 2014 will be about 66,000.
Answer: about 66,000 people
Example 2

8. COLLEGE The line graph shows the annual enrollment at a local college over the last 10 years. If the trend continues, how many students will be enrolled in the college in 2012?
A. about 16,500 students
B. about 17,250 students
C. about 18,000 students
D. about 18,500 students
Example 2 CYP

9. Use a Scatter Plot to Predict
AIR QUALITY The scatter plot shows the number of days that a city failed to meet air-quality standards from 2000 to Predict the number of days of bad air quality in 2014.
Draw a line of best fit that is close to most of the data points.
Answer: The predicted number of days of bad quality for 2014 is about 48.
Example 3

10. The scatter plot shows the number of people who attended a town’s annual pie festival from 2000 to Predict the number of people who will attend the pie festival in 2010.
A. 1,700 people
B. 1,600 people
C. 1,500 people
D. 1,400 people
Example 3 CYP