The selling price would be 99 dollars (rounded to the nearest dollar. It would be $99.45 if it is not rounded).
Step-by-step explanation:
1. 55.25 is the original price in the problem, meaning it is 100%
2. If we need to find 80% of 55.25, we should set up a ration table.
3. 55.25 x
---------- = -------
100 80
4. From here, we need to cross multiply.
-55.25 times 80 is 4,420
-4,420 divided by 100 is 44.2
5. Since 44.20 is 80% of 55.25, we need to add the two prices together, because the store she bought them from marked them up (raised the price)
6. 44.20+55.25=99.45
7. Now, we round to the nearest dollar, which would be 99
Hope this helps!