The unemployment rates in the United states during a 10-year period are given in the following table. Use exponential smoothing to find the best forecast for next year. Use smoothing constants of 0.2, 0.4, 0.6, 0.8. Which one has the lowest MAD?
Year 1 2 3 4 5 6 7 8 9 10
Rate 7.2, 7.0, 6.2, 5.5, 5.3, 5.5, 6.7, 7.4, 6.8, 6.1