Question

The population of the United States was about 280 million in 2000 in about 310 million in 2010. What was the annual rate of change in population from 2000 to 2010?

Answer 1

Rate of change would be:

change population / change in year

310 m - 280 m / 2010 - 2000

30 m / 10

3 m / 1

The change was 3 million per year.