Making Predictions with Line of Best Fit

What is a line of best fit used for?

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. 

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 pages would be in a book with 19 chapters. 

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°?

The scatter plot shows the amount of sleep Aria got the night before a test and her test scores. Which is the best prediction for Aria’s grade when she sleeps for 10 hours?

The scatter plot shows the weight and age of a puppy and a line of best fit. The line of best fit is $$y=2x+1.5$$ where x represents the puppy's age in weeks and y represents the puppy's weight. Predict the weight of a 15-week old puppy in lbs.

(a)  

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

The scatter plot shows the relationship between the number of chapters and the total number of pages for several books. Use the line of best fit to predict how many chapters would be in a book with 140 pages.

What is the equation of the line of best fit?