Making Predictions with Scatterplots

The scatter plot shows the relationship between the number of chapters and the total number of pages for several books.  Use the trend line to predict how many chapters would be in a book with 180 pages. 

• 12 chapters

• 15 chapters

• 18 chapters

• 21 chapters

What is the equation of the line of best fit?

• y = -25x + 170

• y = -5/8x + 170

• y = 25x + 170

• y = 5/8x + 170

The equation of the trend line is y= 1/2x +1

How many laps can a bicycle make around the park in 11 minutes?

• 44 laps

• 12 1/2 laps

• 20

• 23

A researcher gathered data to predict the number of new types of plants (y) that will be in a state park after x years.  After making a scatter plot of the data, she determined the equation of a line of best fit to be
y = 0.25x + 8
Based on the equation, what is the number of new types of plants that will be in the park after 24 years?

• 8

• 14

• 32

• 64

Estimate the correlation coefficient.

• r is close to 1

• r is close to -1

• r is close to 0

• r is close to -0.5

• r is close to 0.5

Estimate the correlation coefficient

• r = 1

• r = -1

• r ≈ -0.8

• r ≈ 0.8

• r ≈ -0.5

What is a scatter plot?

• A graph that shows the relationship of two data sets.

• A graph drawn using rectangular bars to show how large each value is.

• A graph that shows information that is connected in some way.

• A graph that shows data changing over time.

Make a prediction for a resting heart rate after 6 hours of exercise a week.

• 6

• 50

• 55

• 80

Describe the correlation coefficient if

r = 0.90

• Positive, weak

• Positive, strong

• Negative, weak

• Negative, strong

Estimate the correlation coefficient.

• r is close to zero

• r is close to -1

• r is close to 1

• r is close to -1.5

• r is close to 1.5