-15.38% is the change from 650 to 550
Calculation steps:
[( 550 - 650 ) ÷ 650] x 100 = -15.38%
Formula
Percentage change = [(550 - 650) / 650] x 100
Subtract the new number by the original number
550 - 650 = -100
-100 ÷ 650 = -0.15384615384615385
-0.15384615384615385 x 100 = -15.38%