308.33% is the change from 12 to 49
Calculation steps:
[( 49 - 12 ) ÷ 12] x 100 = 308.33%
Formula
Percentage change = [(49 - 12) / 12] x 100
Subtract the new number by the original number
49 - 12 = 37
37 ÷ 12 = 3.0833333333333335
3.0833333333333335 x 100 = 308.33%