ten weeks of data on the commodity futures index are 7.35, 7.40, 7.55, 7.56, 7.60, 7.52, 7.52, 7.70, 7.62, and 7.55. construct a time series plot. what type of pattern exists in the data? use trial and error to find a value of the exponential smoothing coefficient that results in a relatively small mse.