## anonymous 4 years ago how do you find the equation of a line of best fit? please help!!

1. anonymous

Do you have a graph?

2. anonymous

yes

3. anonymous

Exactly what do you need help with?

4. anonymous

i dont know what steps to do in order to find the equation of the line of best fit

5. anonymous

look for the y-intercept first. If the equation is in the form y=mx+b, b is the y-intercept, which is the point the line crosses the graph

6. anonymous

-5.4

7. anonymous

Next look for the slope, m, which is $\frac{y2-y1}{x2-x1}$

8. anonymous

do i get 2 ploted points?

9. anonymous

If you have plotted points, then you can substitute them into that equation for slope

10. anonymous

after that do i just plug the slope and the y-intercept into the equation?

11. anonymous

if you know the slope and the y-intercept, you can identify the graph

12. anonymous

ok thank you so much

13. anonymous

np

14. anonymous

:)

15. amistre64

the mean of your xs and the mean of your ys will be a point on the line of best fit $(\bar x,\bar y)$ is on the line so we just need to determine a good slope to use

16. amistre64

i cant recall how the average slope is obtained; personally I just use excel to calculate the slopes and pick the average fromthe interquartile range ..... but thats not "proper" :)