-78.75% is the change from 400 to 85
Calculation steps:
[( 85 - 400 ) ÷ 400] x 100 = -78.75%
Formula
Percentage change = [(85 - 400) / 400] x 100
Subtract the new number by the original number
85 - 400 = -315
-315 ÷ 400 = -0.7875
-0.7875 x 100 = -78.75%