-51% is the change from 800 to 392
Calculation steps:
[( 392 - 800 ) ÷ 800] x 100 = -51%
Formula
Percentage change = [(392 - 800) / 800] x 100
Subtract the new number by the original number
392 - 800 = -408
-408 ÷ 800 = -0.51
-0.51 x 100 = -51%
Example