9.75% is the change from 400 to 439
Calculation steps:
[( 439 - 400 ) ÷ 400] x 100 = 9.75%
Formula
Percentage change = [(439 - 400) / 400] x 100
Subtract the new number by the original number
439 - 400 = 39
39 ÷ 400 = 0.0975
0.0975 x 100 = 9.75%
Example