29.91% is the change from 642 to 834
Calculation steps:
[( 834 - 642 ) ÷ 642] x 100 = 29.91%
Formula
Percentage change = [(834 - 642) / 642] x 100
Subtract the new number by the original number
834 - 642 = 192
192 ÷ 642 = 0.29906542056074764
0.29906542056074764 x 100 = 29.91%