-70.59% is the change from 170 to 50
Calculation steps:
[( 50 - 170 ) ÷ 170] x 100 = -70.59%
Formula
Percentage change = [(50 - 170) / 170] x 100
Subtract the new number by the original number
50 - 170 = -120
-120 ÷ 170 = -0.7058823529411765
-0.7058823529411765 x 100 = -70.59%