Ricardo gathered income data from a small sample of people 18 years old or older. From the data he collected, Ricardo was able to model income based on a person's age and their number of years of college. His model approximates a person's income, in thousands of dollars, as the square root of the product of 200 and the sum of how much older, in years, than
18 years old a person is and their number of years of college.
Which equation represents Ricardo's model of a person's income, where I represents income in thousands of dollars, a represents age in years, and y represents the number of years
of college?