Question

A regression model with quarterly seasonal dummy variables was fit to quarterly sales data (in $10.000) for a small company. The results are shown below. The dummy variables and other devede are defined as follows: Q1 = 1 if the time period is Quarter 1, and O otherwise. Q2 and 3 are defined similarly. Abbreviations Used in the Output • "R-So" stands for "r squared • "R-Sq" stands for "adjusted rsquared SSE • s stands for "regression standard error," equal to Vn-(p+1) The regression equation is Sales - 136 - 31.0 Q1 - 52.0 02 - 51.2 03 Predictor Constant Coef 136.167 -31.000 -52.000 -51.167 SE Coef 4.822 6.820 6.820 6.820 T P 28.24 0.000 -4.55 0.000 -7.62 0.000 -7.50 0.000 03 S - 11.8121 R-Sq - 79.3% R-Sq(adj) - 76.2% Looking at the estimated regression equation above, which of the following is true? Sales are lowest in the fourth quarter. Sales are lowest in the first quarter. Sales are higher in the first second and third quarters compared with the fourth quarter. Sales are lower in the first second and third quarters compared with the fourth quarter. Sales are neither higher nor lower than average for any quarter.

Answer 1

here since from above output , coefficient of Q1,Q2 and Q3 are negaive , which means , expected sales decreases for Q1,Q2 and Q3,, Correct option is :

Sales are lower in the first, second and third quarters compared with the fourth quarter