Answer:
You will have to pay 13.68 dollars. 
Explanation:
If you take 4.56 you can see that it is automatically 1 dollar because 25% of 4 is 1. After that you're left with 56 cents, so whats 25% of that? Your answer is 14 cents. If you multiply 14 by it comes up to 56. 
So since each box is 3.42, multiply that by 4. 
-Faker