Consider the Following Set of Quarterly Sales Data,given in Thousands

Essay

Consider the following set of quarterly sales data,given in thousands of dollars. The following dummy variable model that incorporates a linear trend and constant seasonal variation was used: y(t)= B₀ + B_1t + B_Q1(Q1)+ B_Q2(Q2)+ B_Q3(Q3)+ E_t.In this model,there are 3 binary seasonal variables (Q1,Q2,and Q3),where Qi is a binary (0,1)variable defined as:
Qi = 1,if the time series data is associated with quarter i;
Qi = 0,if the time series data is not associated with quarter i.The results associated with this data and model are given in the following Minitab computer output.The regression equation is
Sales = 2442 + 6.2 Time − 693 Q1 − 1499 Q2 + 153 Q3 Provide a managerial interpretation of the regression coefficient for the variable "time."