With the curve

parameterized by

with

, and given the vector field

the work done by

on a particle moving on along

is given by the line integral

where

The integral is then


7 oz bag:
110 ÷ 7 = 15.7143¢ per oz
9 oz bag:
146 ÷ 9 = 16.2222¢ per oz
So the answer is the 7 oz bag, hope this helps!
The best way to estimate it is to do "written addition" in your head, adding 1+8, then 9+3, all the way until you get to the front. the actual answer is 189,459, so your answer should be somewhere close to that.