This macro lets you specify a confidence level other than 95% for the prediction intervals for the forecasts when using Winters' Method and a multiplicative model is appropriate.
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The syntax used to run the macro varies slightly depending on the version you are using.
Suppose the data are in C1, the seasonal length is 2, the level, trend, and seasonal weights are .2 .2 .2 respectively, you want 2 forecasts, and you want 99% prediction intervals stored in the Worksheet.
%WINTMULT2 C1 2; WEIGHT 0.2 0.2 0.2; FORECASTS 2; CONF 99.
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