If you would like to know what is the percent change of 40 to 72, you can calculate this using the following steps:
x% of 40 = 72
x% * 40 = 72
x/100 * 40 = 72 /*100/40
x = 72 * 100 / 40
x = 180%
180% - 100% = 80%
The correct result would be an 80% increase.
