Correspond ci n 15 deseasonalizing a series to remove

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Unformatted text preview: actly add to N and correspond to the N seasonal factors. correspond Σ ci = N 15 Deseasonalizing a Series To remove seasonality from a series, simply divide each observation in the series by the appropriate seasonal factor. The resulting series will have no seasonality and may then be predicted using an appropriate method. Once a forecast is made on the deseasonalized series, one then multiplies that forecast by the appropriate seasonal factor to obtain a forecast for the original series. series. Trend = Deseasonilized Actual = Seasonilized Example Monday Tuesday Wednesday Thursday Friday Week 1 16,2 12,2 14,2 17,3 22,5 Week 2 17,3 11,5 15 17,6 23,5 Week 3 14,6 13,1 13 16,9 21,9 Week 4 16,1 11,8 12,9 16,6 24,3 16 Seasonality via Moving Seasonality Averages Averages Period 1 2 3 4 5 6 7 8 Demand 10 20 26 17 12 23 30 22 MA(4) Example Given α = 0.1 and January trend forecast is 400 units. Seasonal Index (SI) for Jan, Feb and March is 0.8 , 0.9 and 1.2 . and Sales in Jan = 344 units Sales in Feb = 414 units Sales in March = ? 17 The Difficulty with The Long-Term Forecasts Long Reading Reading Textbook page 105 - 113 18 Selected Problems 1, 3, 12, 13, 16, 18, 22, 23, 24, 28, 34, 50 19...
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This document was uploaded on 03/23/2014.

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