Question 181767
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Once you have sketched your line, pick two points on your line and determine the coordinates of the two points, *[tex \Large (x_1,y_1)] and *[tex \Large (x_2,y_2)].  If your sketched line passes through one or two of the scatter plot points, that makes it easy.  Otherwise, you will just have to eye-ball it.


Next, use the two-point form of the equation of a straight line to develop your equation:


*[tex \LARGE \text{          }\math y - y_1 = \left(\frac {y_2 - y_1}{x_2 - x_1}\right)(x - x_1)] 


Do all of the indicated arithmetic and then you can either solve for <i>y</i> to give the slope-intercept form:


*[tex \LARGE \text{          }\math y = mx + b]


or arrange it into standard form:


*[tex \LARGE \text{          }\math Ax + By = C]


John
*[tex \LARGE e^{i\pi} + 1 = 0]
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