Relative percent increase - accurate to one decimal place

Question

The population of a town increased from 3750 in 2007 to 5800 in 2012. Find the absolute and relative (percent) increase.

give the answers accurate to atleast one decimal place.

Answer 1

Over the 5 years between 2007 and 2012, the town population changed from 3750 to 5800.

The difference between the 2 values is 5800 - 2750 = 2050, an increase.

Thus the percent increase is 100% * (5800-3750)/3750 = 100% * 2050/3750 = 54.7% from 2007 to 2012..

An alternative way to do this is the find the quotient 5800/3750 = 1.546... and notice that the decimal part shows the amount of difference as a proportion. Since the quotient is greater than 1, the difference denotes an increase. Multiply the decimal part by 100% and you'll get 54.7% as before.

If the quotient was less than 1, the difference would show a decrease. A quotient equal to 1 shows no difference.