A. Use the result of the last problem to show that, if ¯ x an ¯ y are the mean x - and y -coordinates of the data points, then ( ¯ x , ¯ y ) lies on the least-squares, best-fit line. B. The...

A. Use the result of the last problem to show that, if ¯x
an ¯y
are the mean
x- and
y-coordinates of the data points, then ( ¯x
,
¯y) lies on the least-squares, best-fit line.

B. The least-squares solution to the equation
A
c
=
b, for a vector of unknowns
c, is given by ˆc
= (AT A) −1AT

b. You might think this formula could be simplified as

Explain the error in this reasoning.