Based on the information given in the exercise, you can identify that the number that represents the 100% is the following:

Then, let be "x" the percent asked in the exercise.
Using the information given, you can set up the following proportion:

Now you must solve for "x" in order to find its value. To do this, you can use this procedure:
1. Multiply both sides of the equation by 5.5:

2. Divide the numerator by the denominator:

The answer is: 80%