3800% is the change from 20 to 780
Calculation steps:
[( 780 - 20 ) ÷ 20] x 100 = 3800%
Formula
Percentage change = [(780 - 20) / 20] x 100
Subtract the new number by the original number
780 - 20 = 760
760 ÷ 20 = 38
38 x 100 = 3800%
Example