Time-Series Analysis 6-12 Trend Cycle Season Erratic Components Sales Forecasting of December of Next year: 12000×1.05×0.90÷12×1.3=1228.5 征谢纤爱行贸昌大孝 国际商学院市场营销学系Time-Series Analysis Trend Cycle Season Erratic Components Sales Forecasting of December of Next year: 12 000 ×1.05 ×0.90 ÷12 ×1.3=1 228.5 6 －12 6 －12