71.11% is the change from 450 to 770
Calculation steps:
[( 770 - 450 ) ÷ 450] x 100 = 71.11%
Formula
Percentage change = [(770 - 450) / 450] x 100
Subtract the new number by the original number
770 - 450 = 320
320 ÷ 450 = 0.7111111111111111
0.7111111111111111 x 100 = 71.11%