A coffee shop owner wants to estimate demand for the next two quarters for hot chocolate. Sales data consist of trend and seasonality.
a. Quarter relatives are 1.20 for the first quarter, 1.10 for the second quarter, 0.75 for the third quarter , and 0.95 for the fourth quarter. Use this information to deseasonalize sales for quarters 1 through 8.
b. Using the appropriate values of quarter relatives and the equation F_t = 124 + 7.5t for the trend component, estimate demand for periods 9 and 10.