31.15% is the change from 488 to 640
Calculation steps:
[( 640 - 488 ) ÷ 488] x 100 = 31.15%
Formula
Percentage change = [(640 - 488) / 488] x 100
Subtract the new number by the original number
640 - 488 = 152
152 ÷ 488 = 0.3114754098360656
0.3114754098360656 x 100 = 31.15%