-11.25% is the change from 800 to 710
Calculation steps:
[( 710 - 800 ) ÷ 800] x 100 = -11.25%
Formula
Percentage change = [(710 - 800) / 800] x 100
Subtract the new number by the original number
710 - 800 = -90
-90 ÷ 800 = -0.1125
-0.1125 x 100 = -11.25%