280% is the change from 90 to 342
Calculation steps:
[( 342 - 90 ) ÷ 90] x 100 = 280%
Formula
Percentage change = [(342 - 90) / 90] x 100
Subtract the new number by the original number
342 - 90 = 252
252 ÷ 90 = 2.8
2.8 x 100 = 280%
Example