-42.5% is the change from 400 to 230
Calculation steps:
[( 230 - 400 ) ÷ 400] x 100 = -42.5%
Formula
Percentage change = [(230 - 400) / 400] x 100
Subtract the new number by the original number
230 - 400 = -170
-170 ÷ 400 = -0.425
-0.425 x 100 = -42.5%