EXPLANATION
Price of shoes = $5.50
Markup= 40%
Let's call x to the unknown final price.
The markup percentage relationship is given by the following formula:

Replacing terms:

Multiplying both sides by 5.5:

Dividing both sides by 100:

Adding 5.5 to both sides:

Simplifyng the fraction:

Adding numbers:

Switching sides:

Answer: The final price of the shoes in the deparment store is $7.7