74.6% is the change from 315 to 550
Calculation steps:
[( 550 - 315 ) ÷ 315] x 100 = 74.6%
Formula
Percentage change = [(550 - 315) / 315] x 100
Subtract the new number by the original number
550 - 315 = 235
235 ÷ 315 = 0.746031746031746
0.746031746031746 x 100 = 74.6%