A sales coordinator had always been told that 4^th quarter sales were "usually the best of the year" but with significant quarterly fluctuations, it was hard to know whether this had been true "overall" for simply for the most recent couple of quarters. Armed with 20 years of quarterly sales data, the following regression model was generated. In the model, a dummy variable for 4^th quarter was coded.

SUMMARY OUTPUT Regression Statistics Multiple R 0.171213 R Square 0.029314 Adjusted R Square 0.004101 Standard Error 4.097538 Observations 80 ANOVA Significance df SS MS F F Regression 2 39.04206 19.52103 1.16267 0.318078 Residual 77 1292.816 16.78982 Total 79 1331.858 Standard Upper Coefficients Error t Stat P-value Lower 95% 95% Intercept 9.949324 0.954167 10.42724 2.23E-16 8.049335 11.84931 time 0.021684 0.019853 1.092226 0.278139 -0.01785 0.061215 1.082466 1.058725 1.022425 0.309781 -1.02572 3.190656