function error = lsqError(x, y, parameter)
% Objective function for fitting a linear equation to data.
%
% Arguments: x, the input values
%            y, the corresponding measured output values
%            parameter, vector containing slope and intercept 
%                       as the 1st and 2nd element 
%
% Returns: the estimation error in terms of the mean sqaure error

y_est = x .* parameter(1) + parameter(2);
error = meanSquareError(y, y_est);
end