Tires: Humming Tires, nissan 2002, rear tires

Question
My husband purchased 2 new tires for the back of my Nissan 2002 Altima.  The front tires did not need replacement.  The new tires on the back of the car hum like crazy and it is driving me crazy. They are Yokohama and I was told they are fairly good tires.  The size is correct as I have checked with a local tire dealer. Do I need to rotate thes tires? I have never had this problem before.Appreciate any advice you can give me.  

Answer
Linda,

I'm going to guess the humming is really coming from the front tires - and I'll bet they used to be the rear tires.

But first things first.  Measure the tire pressure for all the tires.  Do this yourself so you are sure.  The proper pressure is what's written on a label called the placard, which is usually located on a doorpost or in the glove box.

Then do a real close look (hear?) on where the sound is coming from.  If it is comming from the rear, check the rear alignment.

Hope this helps.