1. Lines of Best Fit

2. Remember this from Friday Lines of Best Fit Most scatterplot are not perfectly linear, but are close enough for us to model with a line. What is a line of Best Fit? Line that approximates the data Where is it on a scatterplot? Through the “center” of the points Why do we need one? Predict outcomes that are not found in the data

3. Sometimes we’ll draw the line for you! 1.What 2 points would you use? 2.Calculate the slope! 3.Pick a point and solve for b 4.Write the line of best fit! 5. If you studied 5.5 hours, what do you think your grade would be? (2, 70) and (4, 85) m = 7.5 b = 55 y = 7.5x + 55 96.25

4. Finding the Line of Best Fit Fast Food Activity as a Class

5. Which line best fits the data in the scatterplot? A.y = 2x – 1 B.y = 2x + 1 C.y = 2x + 2 D.y = 2x + 3 Even though the line of best fit isn’t drawn, can you figure out this answer by looking at the choices?

6. Let’s try one all the way through Approximate a line of best fit for the data. Predict what y would be if x is 20. What points would you use? (5, 2) and (11, 9) If x = 20, then y = 18.74 y = 1.17x -3.85