Raoul has an upcoming school project, and his computer is not working. He needs to use the library computer, and he has estimated that he will need to be on the computer for approximately an hour and a half. How much of a fee can Raoul expect to pay for his computer use at the library?

Raoul will need the computer for a total of 90 minutes.
- The first 30 minutes are free, so Raoul will need to be prepared to pay for 60 minutes.
- This is equal to four intervals of 15 minutes.
- Each 15-minute interval costs $3, so Raoul will need to pay $12 for his Internet usage at the library.