150% is the change from 340 to 850
Calculation steps:
[( 850 - 340 ) ÷ 340] x 100 = 150%
Formula
Percentage change = [(850 - 340) / 340] x 100
Subtract the new number by the original number
850 - 340 = 510
510 ÷ 340 = 1.5
1.5 x 100 = 150%
Example