10. (10 marks) For the time series given in the table below: Use Brown's method (DES) with a 10% smoothing constant to obtain forecast values for all the time periods and for 7-8 and -10 (Use simple initializations f (1) = y, and (1) = 0) [Hint: First obtain 9, (t-1) and e, beginning time period -2 by using the equations: (t-1)=-1(t-1) + B (t 1) and e = y (t-1), and then use the error correction form equations: f(t)=(t-1)+ [1-(1-a)let. B(t)=B(t-1)+ a e] t 1 2 50 51 3 100 Y 4562 75 65 6 170 7 200 Also note that for Brown's method, at time t, the p periods ahead forecast 9t+p(t)is given by: It+p(t) = P(t) + PB (t