175% is the change from 280 to 770
Calculation steps:
[( 770 - 280 ) ÷ 280] x 100 = 175%
Formula
Percentage change = [(770 - 280) / 280] x 100
Subtract the new number by the original number
770 - 280 = 490
490 ÷ 280 = 1.75
1.75 x 100 = 175%
Example