-72.5% is the change from 40 to 11
Calculation steps:
[( 11 - 40 ) ÷ 40] x 100 = -72.5%
Formula
Percentage change = [(11 - 40) / 40] x 100
Subtract the new number by the original number
11 - 40 = -29
-29 ÷ 40 = -0.725
-0.725 x 100 = -72.5%
Example