Suppose that simple exponential smoothing is used to forecast demand from a constant process Y = μ + εt, where Var(εt) = σ^2. Show that the variance of the forecast Ft,t+1 is (α/(2 - α))σ^2 for large values of t. Also find the variance of the forecast error Yt+1 - Ft,t+1: Plot these variance terms as a function of α. Observe that we would like to choose a small α value in order to have a stable forecasting model.