A sample of adults was studied to determine the relationship between education level and annual income. The least-squares regression line for predicting income from education level was computed to be ̂y = 2812 + 3375x, where x is the number of years of education and ̂y is the predicted annual income. The number of years of education among the people in the sample ranged from 8 to 18.

a. If possible, use the least-squares regression line to predict the annual income of a person with 12 years of education. If not possible, explain why not.

b. If possible, use the least-squares regression line to predict the annual income of a person with 6 years of education. If not possible, explain why not.