There WAS a post on the other reflector about doing a prime rib in the oven and asking for help. My response.
I've done over 25 prime ribs in the oven and they are perfect every time.
Get the exact weight of the prime rib. Season it completely and dust some flour on the fat cap. Put in the fridge over night and do not remove until ready to go in the oven. Preheat the oven to 550 degrees. Lets say you have a 10 pound rib. The magic number for med rare is 5. 5 times 10 equals 50 minutes in the oven at 550.
Take the rib from the fridge and put bones down on your roasting pan. Put in the oven and set the timer for 50 minutes. When the timer goes off, turn off the oven but DO NOT OPEN the door for 90 minutes. When 90 minutes is up, take out and behold a crusty rib that is perfectly cooked. Perfect every time.
I personally have the butcher remove the bones, season inside and then tie them back on. Then when you are ready to carve, you just remove the bones and is ready to slice. The following day, I grill the beef ribs with BBQ sauce and WOW! Enjoy Phil I season with Awake-a-Steak........