-24.38% is the change from 320 to 242
Calculation steps:
[( 242 - 320 ) ÷ 320] x 100 = -24.38%
Formula
Percentage change = [(242 - 320) / 320] x 100
Subtract the new number by the original number
242 - 320 = -78
-78 ÷ 320 = -0.24375
-0.24375 x 100 = -24.38%