# Statistics Least Squared - Midterm Tomorrow!

• Sep 30th 2008, 07:36 PM
Dubulus
Statistics Least Squared - Midterm Tomorrow!
By the method of least squares, fit y = Bx to the following n=6 points.

x 3 1 5 6 3 4
y 4 2 4 8 6 5
• Sep 30th 2008, 08:13 PM
TKHunny
How about y = 1.25x. Good luck on that exam.
• Oct 1st 2008, 05:24 AM
Dubulus
how did you decide on 1.25?
• Oct 1st 2008, 05:59 AM
TKHunny
Well, it didn't really matter since your exam is today. If you don't know already, you're probably toast.

I would have preferred y = (36/23) + (41/46)x, with the usual Normal Equations, but you insisted that the intercept is zero, so that limited the choices and the least squares approximation turned out to be y = 1.25x.

Thus: $\displaystyle B \cdot \sum{x^{2}}\;=\;\sum{xy} \implies B\;=\;\frac{120}{96}\;=\;1.25$

Have you met Normal Equations? They ARE important.
• Oct 1st 2008, 04:33 PM
Dubulus
ha you're right i had no idea how to do that problem today! oh well i answered every other question with ease thanks tho