p = amount of change in price
p = (final amount) - (starting amount)
p = 10.12 - 8.84
p = 1.28
The stock increased by $1.28
Divide the value of p over the original amount 8.84
(amount of change)/(original amount) = p/8.84 = 1.28/8.84 = 0.144796
Convert 0.1447 to percent form to get 14.4796% which rounds to 14.5%
Unfortunately 14.5% isn't listed. I think your teacher made an typo when s/he made the problem.
