Suppose the regression line μy = -10,000 + 1000x models the relationship for the population of working adults in Canada between x = age and the mean of y = annual income (in Canadian dollars). The conditional distribution of y at each value of x is modeled as normal, with σ = 5000. Use this regression model to describe the mean and the variability around the mean for the conditional distribution at age
(a) 20 years and
(b) 50 years.