Line of Best Fit
Example Continued

Step 2. Draw a line that seems to best fit the data.

BestFitEx1-3

Step 3. Use two points and find the slope of the line. Use the slope formula m = BestFitEx1-4.

Suppose the points are (9, 260) and (30, 530). You may choose different points. Now calculate the slope through the two points.
BestFitEx1-5

Step 4. Estimate the y-intercept or use a point and the slope found in Step 3 to write the equation. Substitute the slope (m) and the point (x1, y1) into the point-slope form of an equation y - y1 = m (x - x1).

BestFitEx1-6

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