69.39% is the change from 490 to 830
Calculation steps:
[( 830 - 490 ) ÷ 490] x 100 = 69.39%
Formula
Percentage change = [(830 - 490) / 490] x 100
Subtract the new number by the original number
830 - 490 = 340
340 ÷ 490 = 0.6938775510204082
0.6938775510204082 x 100 = 69.39%