-10.2% is the change from 98 to 88
Calculation steps:
[( 88 - 98 ) ÷ 98] x 100 = -10.2%
Formula
Percentage change = [(88 - 98) / 98] x 100
Subtract the new number by the original number
88 - 98 = -10
-10 ÷ 98 = -0.10204081632653061
-0.10204081632653061 x 100 = -10.2%