The actual demand shows a step increase from d1 to d2 at a certain time. Subsequently,

Question

A moving average system is used for forecasting weekly demand. F₁(t) and F₂(t) are sequences of forecasts with parameters m₁ and m₂, respectively, where m₁ and m₂(m₁>m₂) denote the numbers of weeks over which the moving averages are taken. The actual demand shows a step increase from d₁ to d₂ at a certain time. Subsequently,                                            

      (a) neither F₁(t) nor F₂(t) will catch up with the value d₂

      (b) both sequences F₁(t) and F₂(t) will reach d₂ in the same period

      (c) F₁(t) will attain the value d₂

      (d) F₂(t) will attain the value d₂