286.75% is the change from 83 to 321
Calculation steps:
[( 321 - 83 ) ÷ 83] x 100 = 286.75%
Formula
Percentage change = [(321 - 83) / 83] x 100
Subtract the new number by the original number
321 - 83 = 238
238 ÷ 83 = 2.8674698795180724
2.8674698795180724 x 100 = 286.75%