-20% is the change from 425 to 340
Calculation steps:
[( 340 - 425 ) ÷ 425] x 100 = -20%
Formula
Percentage change = [(340 - 425) / 425] x 100
Subtract the new number by the original number
340 - 425 = -85
-85 ÷ 425 = -0.2
-0.2 x 100 = -20%
Example