The line that best fits a correlation follows the same slope as the pattern suggested by the points. The sum of the distances between scatter points and the line of best fit is roughly the same above the line as it is below. To find the equation of the line you just have to find its slope and y-intercept.
In the case of example # 1 below, estimate the coordinates of two points on the line of best fit - say, (55,530) and (268,690). Now use these points to determine the line's slope:
slope = (y2 - y1 )/(x2 - x1 ) =
(690-530)/(268-55) = 160/213 = 0.76
Note that the y-intercept is approximately 500.
So the equation of the line is Y = 0.76X + 500
Enter the slope and y-intercept below and check your work. As you can see, the result is close, but both the value for the slope and the y-intercept are a bit high. Adjust the values and check again as needed.
and check your equation
1) Find the equation of the line of best fit for each of the examples #2-5.