More on Prime Rib...

I have been concerned about removing the roast at an internal temperature of 125* because with a roast that size a standing time of close to 30 minutes would not be too long, and I think the temperature might rise more than my usual 3 rib size. I consulted my newest cookbook on meat called The Complete Meat Cookbook by Bruce Aidells and Denis Kelly. This is a wonderful book, easy to use recipes that work. Any way I am going to quote what they say about the temperature. ( They also recommend 15 minutes at higher temp (450*F) then finishing at 350*F.)
This is for a 6-12 lb bone-in roast. "Roasting to 115 degrees will give you a mostly rare roast, except for the end cuts, which will be medium-rare to medium; you can roast it a little longer to 120* to 125* if you like it a little more done, but be careful not to overcook it. Remove the roast from the oven and cover it loosely with foil. Let it rest for at least 15 minutes and up to 30 minutes. During this time the retained heat will continue to cook the roast and the juices within the roast will stabilize. After 15 minutes, if you removed the roast at 115*, the internal temperature will have risen to 125*F. After 30 minutes the internal temperature may even read 130*F, which is still rare to medium rare."
Assuming the internal temperature you are hoping to achieve is 130*, you could roast to some where in the 120*F/122*F range and keep an eye on it during the resting time.