What straight line best fits the data.....?

X = [1 1;1 1; 3 1; 4 1], A = {a; b} = ?; Y = [0; 1; 1; 2]

A = (X^t * X)^-1 * X^t * Y = {4/9 0}

y(x) = 4x/9 + 0 = 4x/9

Given:
x: 1 1 3 4
y: 0 1 1 2
=>
the best fit of the straight line is
y=0.44444x

0.444444 x