**Least Squares Line**

The least square line

Y = mx + b

that gives the best fir to the data points

(x_{1} , y_{1}) , (x_{2} , y_{2}) ,…….(x_{n} , y_{n})

has slope m and y-intercept b that satisfy the equations

nb + (∑x)m = ∑y

(∑x)b + (∑x^{2})m = ∑xy.