Hi
It seems like your college wants you to make use of these 4 amplifiers to build a two way communication system, which means that these 4 amplifiers will be placed, two on each side, in order to amplify the signal when transmitted or received. This genreally happens in a two way communication system. So here is how you should proceed:
1. Set-up two audio amplifiers on each side of the two way communication system
2. Use twisted pair cable wire as the medium of communication
Also 4ohm7 means 4.7ohms, it is a short-hand form of mentioning resistor values.