The confidence interval is based on mean square error. T<span>he </span>mean squared error<span> (</span>MSE<span>) </span><span>of an </span>estimator<span> measures the </span>average<span> of the squares of the </span>errors<span> or </span>deviations.<span> MSE is calculated by the formula attached in the picture, where Xbar is a vector of predictions, X is the vector of predicted values. </span>
