97.44% is the change from 390 to 770
Calculation steps:
[( 770 - 390 ) ÷ 390] x 100 = 97.44%
Formula
Percentage change = [(770 - 390) / 390] x 100
Subtract the new number by the original number
770 - 390 = 380
380 ÷ 390 = 0.9743589743589743
0.9743589743589743 x 100 = 97.44%