1A) The output displayed above is a quarterly seasonal and trend model of real monthly corn prices (1982 $/bu.) as the dependent variable. Explanatory variables include a yearly time trend and three quarterly dummy variables Q1, Q2, and Q3 that are equal to 1 if the observation is in the first, second, or third quarter of the year respectively, and equal to 0 otherwise. Looking at the output above, write down the estimated regression equation in mathematical form.1B) what percent of the variability in corn prices is explained by this model?1C) What is the interpretation of the parameter estimate of 0.17 for Q2? What is the interpretation of the parameter estimate of -0.02 for the Year time trend variable?1D) Which of the parameter estimates are statistically significant at the 95% level?

Summary Output Regression Statistics Multiple R 0.4048 R Square 0.1639 Adjusted R Square 0.1570 Standard Error 0.6006 Observations 488 ANOVA df SS MS F Significance F Regression 4 34.1528 8.5382 23.6694 0.0000 Residual 183 174.2314 0.3607 Total 487 208.3842 Coefficients Std Error t Stat P-Value Interdept 2.1816 0.0725 30.0787 0.0000 Q1 0.1255 0.0771 1.6278 0.1042 Q2 0.1705 0.0771 2.2117 0.0275 Q3 0.0947 0.0772 1.2268 0.2205 Year 0.0220 0.0023 -9.4938 0.0000