Consider a linear regression model where yrepresents the response variable, x is a numerical explanatory variable, and dis a dummy variable. The model is estimated as y = 16.3 + 3.6x - 4.2d. a. Interpret the dummy variable coefficient. O Intercept shifts down by 4.2 units as d changes from 0 to 1. O Slope shifts down by 4.2 units as d changes from 0 to 1. O Intercept shifts up by 4.2 units as d changes from 0 to 1. O Slope shifts up by 4.2 units as d changes from 0 to 1. b. Compute y for x= 1 and d=1. (Round your answer to 1 decimal place.) c. Compute y for x=1 and d= 0. (Round your answer to 1 decimal place.)