-73.33% is the change from 15 to 4
Calculation steps:
[( 4 - 15 ) ÷ 15] x 100 = -73.33%
Formula
Percentage change = [(4 - 15) / 15] x 100
Subtract the new number by the original number
4 - 15 = -11
-11 ÷ 15 = -0.7333333333333333
-0.7333333333333333 x 100 = -73.33%