The population of a city increased from 21,500 to 31,900 between 2004 and 2012. Find the change of population per year if we assume the change was constant from 2004 and 2012.

Answer 1

First, you have to find the total population increase by subtracting the population in 2004 (21,500) from the population in 2012 (31,900). This would be 31,900 - 21,500 = 10,400.

Next, you need to determine how many years went by (2012 - 2004 = 8). Finally, you divided the total population increase by the number of years over which the population increased. This would be 10,400 / 8 = 1300. Therefore, the annual population change was +1300 (the population went up by 1300 annually).