Forecasting Methods: Multiplicative Seasonal Forecasting

Q$1$: The manager of the automobile company needs a quarterly forecast of the number of customers expected next year. The business is seasonal, with a peak in the third quarter and a through in the first quarter.

The manager wants to forecast customer demand for each quarter of year $5,$ based on an estimate of total year $5$ demand of $360$ customers.

The table on the following slides shows the quarterly demand data from the past $4$ years. Calculate the quarterly demand for year $5$ using multiplicative seasonal forecasting method $($rounded up to $3$ d$$cimal places$).$

Steps $1$: Find Average Quarterly Demand

Step $2$: Find Seasonal Factor