Least Squares Line

[Tiger-T]

Find an equation for the least squares line representing weight, in pounds, as a function of height, in inches, of men. Then, predict the height of a man who is 145 pounds to the nearest tenth of an inch. The following data are the (height, weight) pairs for 8 men: (66, 150), (68, 160), (69, 166), (70, 175), (71, 181), (72, 191), (73, 198), (74, 206).
Solutions are:
A) 63.2 inches
B) 68.2 inches
C) 65.7 inches
D) 64.6 inches
I also need to know how the answer was resloved! Or at least tell and show me how to figure the answer! Thank you in advance!

 

[galactus]

Use Excel, or some other tech, to perform a linear regression. By entering the data into Excel or calculator, you can find the line equation. The formulas to do this by hand are cumbersome. This is why it is usually done with tech of some sort.
A lot of calculators these days do regressions.

Just using my TI, I get \(\displaystyle y=7.215539x-329.418546\)

This has an R^2 of .99

That is pretty good. The closer it is to 1, the better.

Set the equation equal to 145 and solve for x.

Do you have Excel?. If so, I can explain to you how to do a linear regression with it.

 

[Tiger-T]

Galagtcus,

Yes I have excel. I think I just completed a similar problem. I am going to try it using excel. Thank you so much for your assistance!