50.9% is the change from 279 to 421
Calculation steps:
[( 421 - 279 ) ÷ 279] x 100 = 50.9%
Formula
Percentage change = [(421 - 279) / 279] x 100
Subtract the new number by the original number
421 - 279 = 142
142 ÷ 279 = 0.5089605734767025
0.5089605734767025 x 100 = 50.9%