Final answer:
To use exponential smoothing with an alpha of 0.2, you apply the given formula with the current period's actual sales and last period's forecast. Without the actual sales figure for the current period, the forecast for the next period cannot be calculated exactly.
Step-by-step explanation:
To forecast this month's sales using exponential smoothing with an alpha of 0.2, and given that August's forecast was 145, you would use the formula:
Ft+1 = α × At + (1 - α) × Ft
Where:
- Ft+1 is the forecast for the next period.
- α is the smoothing constant (in this case, 0.2).
- At is the actual sales figure for the current period (which is not provided).
- Ft is the forecast for the current period (which was 145).
Since we do not have the actual sales figure for the current period (At), we cannot calculate the forecast for the next period precisely. However, the process to update the forecast when the actual sales are known would be to insert the actual sales figure into the formula and compute the new forecast.