30.53% is the change from 642 to 838
Calculation steps:
[( 838 - 642 ) ÷ 642] x 100 = 30.53%
Formula
Percentage change = [(838 - 642) / 642] x 100
Subtract the new number by the original number
838 - 642 = 196
196 ÷ 642 = 0.3052959501557632
0.3052959501557632 x 100 = 30.53%