Final answer:
The construction crew has paved 4 miles of highway.
Step-by-step explanation:
To convert feet to miles, divide the number of feet by 5,280. In this case, the construction crew has paved 21,120 feet of highway, so to find the number of miles paved, we divide 21,120 by 5,280:
21120 ÷ 5280 = 4
Therefore, the construction crew has paved 4 miles of highway.
Learn more about converting feet to miles