27.57% is the change from 642 to 819
Calculation steps:
[( 819 - 642 ) ÷ 642] x 100 = 27.57%
Formula
Percentage change = [(819 - 642) / 642] x 100
Subtract the new number by the original number
819 - 642 = 177
177 ÷ 642 = 0.2757009345794392
0.2757009345794392 x 100 = 27.57%