-50% is the change from 782 to 391
Calculation steps:
[( 391 - 782 ) ÷ 782] x 100 = -50%
Formula
Percentage change = [(391 - 782) / 782] x 100
Subtract the new number by the original number
391 - 782 = -391
-391 ÷ 782 = -0.5
-0.5 x 100 = -50%
Example