-74% is the change from 50 to 13
Calculation steps:
[( 13 - 50 ) ÷ 50] x 100 = -74%
Formula
Percentage change = [(13 - 50) / 50] x 100
Subtract the new number by the original number
13 - 50 = -37
-37 ÷ 50 = -0.74
-0.74 x 100 = -74%
Example