-20% is the change from 155 to 124
Calculation steps:
[( 124 - 155 ) ÷ 155] x 100 = -20%
Formula
Percentage change = [(124 - 155) / 155] x 100
Subtract the new number by the original number
124 - 155 = -31
-31 ÷ 155 = -0.2
-0.2 x 100 = -20%
Example