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 Sales = β₀ + β₁Qtr1 + β₂Qtr2 + β₃Qtr3 + β₄t + ε, with dummy variables Qtr1, Qtr2, and Qtr3, is used to make forecasts. For the regression model, the following partial output is available. What is the regression equation for the linear trend model with seasonal dummy variables?

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 Sales = β₀ + β₁Qtr1 + β₂Qtr2 + β₃Qtr3 + β₄t + ε, with dummy variables Qtr1, Qtr2, and Qtr3, is used to make forecasts. For the regression model, the following partial output is available.

What is the regression equation for the linear trend model with seasonal dummy variables?

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 Sales = β₀ + β₁Qtr1 + β₂Qtr2 + β₃Qtr3 + β₄t + ε, with dummy variables Qtr1, Qtr2, and Qtr3, is used to make forecasts. For the regression model, the following partial output is available. What is the regression equation for the linear trend model with seasonal dummy variables?

Quarterly Sales of a Department Store for the Last Seven