8.5% is the change from 400 to 434
Calculation steps:
[( 434 - 400 ) ÷ 400] x 100 = 8.5%
Formula
Percentage change = [(434 - 400) / 400] x 100
Subtract the new number by the original number
434 - 400 = 34
34 ÷ 400 = 0.085
0.085 x 100 = 8.5%
Example