-38.75% is the change from 800 to 490
Calculation steps:
[( 490 - 800 ) ÷ 800] x 100 = -38.75%
Formula
Percentage change = [(490 - 800) / 800] x 100
Subtract the new number by the original number
490 - 800 = -310
-310 ÷ 800 = -0.3875
-0.3875 x 100 = -38.75%