best fit line?

Question

Determine the slope of the best-fit line for the following data:

X Y
2 21
4 0
6 -9
8 -12

Answer 1

The equation of the best fit line would be:

y = -5.4x + 27

Therefore, the slope is -5.4

Answer 2

well.

either you've been given the classical linear regression formulas in your class, to get the slope, the y intercept, and the residuals.

or, you've been given a tool, such as Excel, or a calculator, to find the parameters for such a line. In Excel, if you do Tools, Data Analysis, Regression, you'll get, for these points:

y intercept = b = 27

slope = a = -5.4

so the equation for your best fit line is
y = -5.4x + 27


hope this helps

Answer 3

you have to plot the points on a graph and then draw a line going through the points or draw a line that would be closest to all the points and then just find the rise/run from one point to another. rise meaning up the y axis and run meaning right across the x axis to your other point. then if you have to simplify the slope.