Answer:
Approx. 59% increase.
Explanation:
Today - 221
Yesterday - 139
difference (today - yesterday) = 82
How to find percent:
((part)/(whole)) = ((x)/(100))
In this case, the part is the difference, and the whole is the value of an item yesterday, so the equation is:
82/139 = x/100
cross multiply
8200 = 139x
Inverse operations
8200 = 139x
/139 /139
8200/139 = x
approx. 59 = x