Problem:
The business analyst for Ace Business Machines, Inc. wants to forecast this year's demand for manual typewriters based on the following historical data:
TIME PERIOD------- DEMAND
5 years ago--------------- 900
4 years ago--------------- 700
3 years ago--------------- 600
2 years ago--------------- 500
Last year---------------- 300
What is the forecast for this year using trend adjusted (double) smoothing with alpha(1) = 0.3 and alpha(2) = 0.2, if the forecast for last year was 310, the forecast for two years ago was 430, and the trend estimate for last year's forecast was -150?
* Please use 310, 430, -150 instead (if the forecast for last year was 310, the forecast for two years ago was 430, and the trend estimate for last year's forecast was -150).