are there Shocks and struts on the back?

Look it up on what? I thought people on here would know

Use an internet parts look up to determine whether you have struts or shocks on the rear. The squeak is more likely your springs.

Online auto parts websites are the place to go. NAPA, O'Reilly's, Rock Auto etc.

My brother checked out the rear bushings for the squeak and they look fine. The squeak you can hear if you push up and down in the back of the car. So what could it be? Springs? Struts? Do struts squeak?

Took it to brakes plus. They said the front struts/shocks are squeaking. The tighten or loosen the bolt. The noise is still there. Don't know what is wrong....or where to take it to get it fixed. I am in Omaha. Any suggestions?

Bolts should be torqued to the vehicles specs. Don't just loosen them arbitrarily. It still sounds like your squeek is coming from one of the springs. They tend to rub against their mounting plate and are under variable forces depending on the load you are carrying. It is only an annoyance and will not affect the drivability of your vehicle. I would change out your springs and whichever shocks/struts you have not done yet.