-6.49% is the change from 770 to 720
Calculation steps:
[( 720 - 770 ) ÷ 770] x 100 = -6.49%
Formula
Percentage change = [(720 - 770) / 770] x 100
Subtract the new number by the original number
720 - 770 = -50
-50 ÷ 770 = -0.06493506493506493
-0.06493506493506493 x 100 = -6.49%