139.29% is the change from 280 to 670
Calculation steps:
[( 670 - 280 ) ÷ 280] x 100 = 139.29%
Formula
Percentage change = [(670 - 280) / 280] x 100
Subtract the new number by the original number
670 - 280 = 390
390 ÷ 280 = 1.3928571428571428
1.3928571428571428 x 100 = 139.29%