Make Predictions with Lines 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

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

Which of the following lines represents the line of best fit for the scatter plot?

• A

• B

• C

• D

Tags

CCSS.8.EE.B.5

The red line represents the line of best fit for the scatter plot. How many ice cream sales are expected if the temperature is 90°?

• 55

• 0

• 103

• 100

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

Tags

CCSS.8.EE.B.5

What is the equation of the line of best fit?

• y= 6x + 2

• y = -2x +6

Tags

CCSS.8.EE.B.5

The graph illustrates the number of acres used for forming in Smalltown, New York, over several years.

Using a line of best fit, approximately how many acres will be used for farming in the 5th year? ​ (a)  

Tags

CCSS.HSF-BF.B.4A

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

• Yes

• No

Tags

CCSS.8.EE.B.5

Using your line of best fit equation from the last question, what is y when x is 30?

• 61.59

• 52.46

• 57.94

• 59.76