1. Scatter Plots Line of Best Fit
Teacher Twins©2014

2. Warm Up Make a scatter plot of the data and tell the relationship.
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3. Scatter Plots
Line of Best Fit

4. Line of Best Fit
A straight line that best represents the data on a scatter plot.

5. To draw a line of best fit draw a line that goes through the data and best represents the data. Try to get at least two points on the line.
Green line is too far above most of the data.
Red line is too far below most of the data.

6. Write an equation for the line of best fit.
Get two points from the line.
(1,60), (3,90)

7. (1,60), (3,90)
Find the slope and y intercept to write the equation of the line of best fit.
m = 90 – 60
3 - 1
Pick a point and use the slope to find b.
m = 15, (1,60) Plug into y = mx + b
60 = 15(1) + b b = 45
y = 15x + 45

8. Write a line of best fit for the data.
(1,13)
(13,5)

9. Practice Draw a scatter plot for the data and find a line of best fit.x y 3 85 1 70 5 92 4 90 2 75 60 80
Compare different equations from different ordered pairs.

10. Closure Graph the data and find the line of best fit.
(1, 20), (9,3), (6, 5), (2, 17), (8,2), (4, 7), (3, 10)