Construct Line of Best Fit

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

Which scatter plot shows a linear relationship between x and y?

• Graph A

• Graph B

• Graph C

• Graph D

What is a line of best fit used for?

• To make predictions

• To make the graph look pretty

• To connect the points

• To make it look like you know what you are doing

Write the linear regression equation for the following data points. Round to the nearest hundredth.

Which of the following could be a possible line of best fit for the data?

• y = 3x + 0

• y = 5/6x + 490

• y = -2x + 470

• non linear

Imagine you're helping Zoe, Mia, and Isla find the perfect line of best fit for their scatter plot project. Which of the following lines do you think will earn them an A+?

• A

• B

• C

• D

Answer explanation

Line C is the best choice as it closely follows the trend of the data points in the scatter plot, minimizing the distance from the points to the line, which is essential for a strong line of best fit.

• y = x ; 20
• y = x + 2 ; 22
• y = 2 ; 2
• y = 0.5x + 2 ; 12

• y = 1.45x + 22
• y = -2x + 15
• y = 1.33x + 30
• y = -1.5x + 24

What is the equation of the line of best fit?

• y= 6x + 2

• y = -2x +6

Is this line an accurate line estimate of best fit for the data?

• Yes

• No