Forecast the Sales of Sweaters Essay Questions
The data file sweater.xls shows the quarterly sales of sweaters of a large apparel store in the past 3 years (in 1000s units)
- Construct a time series plot. What type of pattern exists in the data?
- Use a multiple regression model with dummy variables as follows to develop an equation to account for seasonal effects in the data. Qtr1=1 if quarter 1, 0 otherwise; Qtr2=1 if quarter 2, 0 otherwise; Qtr3=1 if quarter 3, 0 otherwise.
- Use a multiple regression model to develop an equation to account for trend and seasonal effects in the data. Use the dummy variables you developed in part b to capture seasonal effects and create a variable t such that t =1 for quarter 1 in year 1, t =2 for quarter 2 in year 1, . . . t =12 for quarter 4 in year 3.
- Calculate MSE for both models. Which model (b or c) is more accurate? Why?
- Forecast the sales of sweaters for Year 4, Quarters 1, 2, 3, 4.
POST
Year Quarter Sales of Sweaters (1000 of units)1181251371482192262382411311232933103411.