5-21 Sales of Cool-Man air conditioners have grown steadily during the past 5 years:

Year Sales 1 450 2 495 3 518 4 563 5 584 6 ?

The sales manager had predicted, before the business started, that year 1’s sales would be 410 air conditioners. Using exponential smoothing with a weight of develop forecasts for years 2 through 6.