81.47% is the change from 421 to 764
Calculation steps:
[( 764 - 421 ) ÷ 421] x 100 = 81.47%
Formula
Percentage change = [(764 - 421) / 421] x 100
Subtract the new number by the original number
764 - 421 = 343
343 ÷ 421 = 0.8147268408551069
0.8147268408551069 x 100 = 81.47%