In this word problem, we estimate the rate at which the total personal income is rising in the Richmond, Petersburg, Virginia, and metropolitan area in 1999, the population of this area was 961,400. The population was increasing at roughly 9200 people per year. The average annual income was 30,593 per capita, and this average was growing at about 1400 per year (a little about the national average of revised 1225 yearly). Use the product rule and these figures to estimate the rate at which total personal income rose in the Richmond Petersburg area in 1999. explain the meaning of each term in the product rule.