-57.5% is the change from 40 to 17
Calculation steps:
[( 17 - 40 ) ÷ 40] x 100 = -57.5%
Formula
Percentage change = [(17 - 40) / 40] x 100
Subtract the new number by the original number
17 - 40 = -23
-23 ÷ 40 = -0.575
-0.575 x 100 = -57.5%
Example