-11.25% is the change from 320 to 284
Calculation steps:
[( 284 - 320 ) ÷ 320] x 100 = -11.25%
Formula
Percentage change = [(284 - 320) / 320] x 100
Subtract the new number by the original number
284 - 320 = -36
-36 ÷ 320 = -0.1125
-0.1125 x 100 = -11.25%