Since there are 16 ounces in a solid pound (remember, lb = 16) our first step will be to find out how much it costs per ounce.

Now we know that the lettuce costs $0.0431 per ounce.
Since the head is 13 ounces, we can now multiply the cost per ounce by the number of ounces.

After rounding, we find that the head of lettuce costs a grant total of $0.56 (56 cents).