must all 4 tires be balanced

They are correct. A very good quality tire, like a Michelin, allot of times won't need any weights to balance it. If they do, it's usually a very small 1/4 ounce weight. Not allot of tires can say that.

That is right, the tire and wheel may be factory indicated for best assembly, then reading that correctly can lead to little or no weight. after setting tire pressure by the sticker, a road test can tell if you need anything.

thanks for that answer, purchased the tires last September the brand is General all was fine and now the car rear passenger is noisy like it needs balancing... and again like I said was told by the tire shop it does not so I guess I am puzzled..

Yeah, that's a kinda rare deal, but still possible for a General tire not needing any weight to balance. Btw, I'm not downing your choice of tires, as that's what I have on one of mine. When you said RR is "Noisey", what kinda noise are we talking about? Roaring noise?.....or like a basketball? lol

Tires that are noisy may be improperly inflated, poorly aligned and wearing oddly or cupped. a smooth feel for your hand across the tread tried 4 ways should be felt to and fro and left and right. if it looks or feels choppy, it is way beyond time to rotate, balance, or align. Rear toe especially can cause uneven wear and be knocked out simply by backing up into a parking curb, or crossing a divider. even hitting dumdums at speed. Your tire dealer may, psi, inspect, rotate, (even balance?) a set of tires you buy but they nowadays dont have an alignment machine. Many will send you to a full service shop or your dealer, of course is the best because they are highly trained and survive on accuracy when fully manned by union journeymen. Can't tell that's where I worked, huh...........But if you need a quick look and an opinion ask there. or a full service tire store.

Now if you can get them to road test with you and you point out this noise, it can get you a fast answer. they may lift the vehicle and inspect tread, tire pressure, brakes, wheel bearings to find it, or just reattach a mud flap for all I can say for sure. even wheel covers or hubcaps lead to the cause of unusual noiseat dealerships all the time. They are more adept from experience and not allowed to say no, or give you lame excuses about we dont do that here, their lube guys are service minded, not commission payed. Csi wins the day there.