Using 20 observations, the following regression output is obtained from estimating y = B + B1X + B20 + B3xd + E. Intercept Coefficients 13.60 3.36 -5.67 3.48 Standard Error 3.20 0.42 6.75 0.75 t Stat p-value 4.25 0.001 8.00 0.000 -0.84 0.413 4.64 0.000 d xd a. Compute for x = 9 and d = 1; then compute for x= 9 and d= 0. (Round intermediate calculations to at least 4 decimal places and final answers to 2 decimal places.) x = 9 and d = 1 x = 9 and d = 0 b-1. Is the dummy variable d significant at the 5% level? Yes, since we reject the relevant null hypothesis. Yes, since we do not reject the relevant null hypothesis. O No, since we reject the relevant null hypothesis. No, since we do not reject the relevant null hypothesis. b-2. Is the interaction variable xd significant at the 5% level? Yes, since we reject the relevant null hypothesis. Yes, since we do not reject the relevant null hypothesis. No, since we reject the relevant null hypothesis. No, since we do not reject the relevant null hypothesis