-28% is the change from 400 to 288
Calculation steps:
[( 288 - 400 ) ÷ 400] x 100 = -28%
Formula
Percentage change = [(288 - 400) / 400] x 100
Subtract the new number by the original number
288 - 400 = -112
-112 ÷ 400 = -0.28
-0.28 x 100 = -28%
Example