Exercise 17-1 Algo 7 Consider a linear regression model where y represents the response variable, x is a quantitative explanatory variable, and dis a points dummy variable. The model is estimated as y =16,3 + 3.6x - 4.2d. a. Interpret the dummy variable coefficient. Intercept shifts down by 4.2 units as d changes from 0 to 1. Slope shifts down by 4.2 units as d changes from 0 to 1. Intercept shifts up by 4.2 units as d changes from 0 to 1. Slope shifts up by 4.2 units as d changes from O 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.)