1. The following are temperature measurements made every minute on a chemical reactor: 200, 202, 208, 204, 204, 207, 207 , 204, 202, 199, 201, 198, 200, 202, 203, 205, 207, 21 10, 508 0, 187 0. 0469, (a) Calculate the sample ACF for the first five lags. 0. 1 80, 0 451 (b) Identify a suitable model. Specify the reason for your answer. (c) Use the method of moment to estimate the model at (b) if it is available, or specify the reason why it is not available. [Total: 10 marks]