Consider the following to answer the question(s) below:
Quarterly sales data (in $10,000) for a small company specializing in green cleaning products are shown in the time series graph below. A seasonal regression model was fit to these data and the results are shown below.
The regression equation is Sales = 89.06 + 1.37t - 23.37Q2 - 23.91Q3 + 27.88Q4.
-The regression coefficients in the seasonal regression model indicate that
A) sales are, on average, lower in the first, second and third quarters compared with the fourth quarter.
B) sales are, on average, lowest in the fourth quarter.
C) sales are, on average, higher in the first, second and third quarters compared with the fourth quarter.
D) sales are, on average, lowest in the first quarter.
E) sales are, on average, lowest in the third quarter.

Question

Consider the following to answer the question(s) below:
Quarterly sales data (in $10,000) for a small company specializing in green cleaning products are shown in the time series graph below.  A seasonal regression model was fit to these data and the results are shown below.
The regression equation is Sales = 89.06 + 1.37t - 23.37Q2 - 23.91Q3 + 27.88Q4. 
-The regression coefficients in the seasonal regression model indicate that
A) sales are, on average, lower in the first, second and third quarters compared with the fourth quarter. 
B) sales are, on average, lowest in the fourth quarter. 
C) sales are, on average, higher in the first, second and third quarters compared with the fourth quarter. 
D) sales are, on average, lowest in the first quarter. 
E) sales are, on average, lowest in the third quarter.

Quizplus · Accepted Answer

The regression coefficients in a seasonal regression model represent the average difference in the dependent variable (e.g., sales) for each category (e.g., quarters) compared to a reference category. If the coefficients for the first, second, and third quarters are negative or lower than the coefficient for the fourth quarter, it indicates that sales are, on average, lower in these quarters compared to the fourth quarter.

Consider the Following to Answer the Question(s) Below