342.86% is the change from 70 to 310
Calculation steps:
[( 310 - 70 ) ÷ 70] x 100 = 342.86%
Formula
Percentage change = [(310 - 70) / 70] x 100
Subtract the new number by the original number
310 - 70 = 240
240 ÷ 70 = 3.4285714285714284
3.4285714285714284 x 100 = 342.86%