100% is the change from 391 to 782
Calculation steps:
[( 782 - 391 ) ÷ 391] x 100 = 100%
Formula
Percentage change = [(782 - 391) / 391] x 100
Subtract the new number by the original number
782 - 391 = 391
391 ÷ 391 = 1
1 x 100 = 100%
Example