-38.63% is the change from 642 to 394
Calculation steps:
[( 394 - 642 ) ÷ 642] x 100 = -38.63%
Formula
Percentage change = [(394 - 642) / 642] x 100
Subtract the new number by the original number
394 - 642 = -248
-248 ÷ 642 = -0.3862928348909657
-0.3862928348909657 x 100 = -38.63%