by multiplying 16 by 0.965 (as it is a 4.5% decrease per year) and then multiplying the answer by 0.965 and so on until done a total of 10 times gets you the answer 11.2 gallons. there is a quicker way to do it but I cannot remember sorry
Since 1990, the number of gallons of whole milk each person in the United States drinks has decreased 4.5% each year. In 1990, each person drank an average of 16 gallons of milk each year. Therefore, the approximate milk consumption of the average person in 2000 is 11.2 gallons.
