I have been given a formula to compute the squared error of smoothed sequences with the help of the "method of least squares".
There is a sigma $(S_i-X_i)^2$. I have been told that sigma means sum. Does this mean that i need to sum the squared value of (the difference between the smoothed sequence minus demand) of each available row and then take the root?
Example:
Demand --- Smoothed sequence
$165$ --- $163$
$171$ --- $164$
Squared error
$\sqrt{(((163-165)^2 + (164-171)^2)/2)}$
Many thanks in advance.