Quarterly sales of a department store for the last seven years are given in the following table. The scatterplot shows that the quarterly sales have an increasing trend and seasonality. A linear regression model given by Sales = β₀ + β₁Qtr1 + β₂Qtr2 + β₃Qtr3 + β₄t + ε, where t is the time period (t = 1, ..., 28) and Qtr1, Qtr2, and Qtr3 are quarter dummies, is estimated and then used to make forecasts. For the regression model, the following partial output is available. Using the regression equation for the linear trend model with seasonal dummy variables, what is the sales forecast for the first quarter of Year 8?

Question

Quarterly sales of a department store for the last seven years are given in the following table.

The scatterplot shows that the quarterly sales have an increasing trend and seasonality. A linear regression model given by Sales = β₀ + β₁Qtr1 + β₂Qtr2 + β₃Qtr3 + β₄t + ε, where t is the time period (t = 1, ..., 28) and Qtr1, Qtr2, and Qtr3 are quarter dummies, is estimated and then used to make forecasts. For the regression model, the following partial output is available.

Using the regression equation for the linear trend model with seasonal dummy variables, what is the sales forecast for the first quarter of Year 8?

Quizplus · Accepted Answer

The Answer of Quarterly sales of a department store for the last seven years are given in the following table. The scatterplot shows that the quarterly sales have an increasing trend and seasonality. A linear regression model given by Sales = β₀ + β₁Qtr1 + β₂Qtr2 + β₃Qtr3 + β₄t + ε, where t is the time period (t = 1, ..., 28) and Qtr1, Qtr2, and Qtr3 are quarter dummies, is estimated and then used to make forecasts. For the regression model, the following partial output is available. Using the regression equation for the linear trend model with seasonal dummy variables, what is the sales forecast for the first quarter of Year 8?

Quarterly Sales of a Department Store for the Last Seven