39.6% is the change from 250 to 349
Calculation steps:
[( 349 - 250 ) ÷ 250] x 100 = 39.6%
Formula
Percentage change = [(349 - 250) / 250] x 100
Subtract the new number by the original number
349 - 250 = 99
99 ÷ 250 = 0.396
0.396 x 100 = 39.6%
Example