This time Math!

[CrazCo]

How do I find the correlation and regression for this linear graph.

X: 0 , 100 , 200 , 300 , 400 , 500 , 600 , 700 , 800 , 900 , 1000

Y: 20 , 19 , 18 , 18 , 17 , 16.5 , 16 , 15 , 14.5 , 13.7 , 13

 

The ones lined up are the coordinates. Anyone can guide me as to how to find the answer?

[ydoaPs]

Take two of the points and find the rate of change(m) by the equation [math]m=\frac{{y_1}-{y_2}}{{x_1}-{x_2}}[/math]. Then plug m, an x value and the corresponding y value into the equation y=mx+b and solve for b. Then you have m and b and it should be ridiculously obvious how to get the equation from there.

[CrazCo]

Hmm maybe we weren't suppose to find the equation then.. we were told to use and TI 84 Plus and that seems too easy

[NeonBlack]

Since not all of the points fall on the same line, they probably want you to use your calculator to do a best fit.

I'm unfamiliar with the 84+ so I'm afraid I can't help you any more than that. See if you can find the documentation on the TI website and search it for 'best fit'

[CrazCo]

English is my second language so I don't really know what you mean by best fit? like "mieux ajustée?"

 

oops i guess we have to find the correlation and regression..

[NeonBlack]

I don't have much mathematics vocabulary in French, so I don't know what you call it, but yes "regression" is essentially the same as best fit.

[CrazCo]

I got y = -0.0067x+19.78

 

19.78 was rounded btw.. i dont know if its right though :S

 

thanks for the help Neon!