40% is the change from 280 to 392
Calculation steps:
[( 392 - 280 ) ÷ 280] x 100 = 40%
Formula
Percentage change = [(392 - 280) / 280] x 100
Subtract the new number by the original number
392 - 280 = 112
112 ÷ 280 = 0.4
0.4 x 100 = 40%
Example