This method is said to work for any size prime rib. The meat is brought to room temperature (this is critical), and seasoned anyway you like. Then you multiply the exact weight times 5 minutes. For me it was 3.75 x 5 = 18.75 minutes. The roast is cooked at 500 degrees F. for exactly that many minutes. The heat is turned off, and you wait 2 hours without opening the oven door.
Once you remove the prime rib, you'll be slicing into the juiciest, tenderest, most perfectly medium-rare meat you've ever seen. If you are looking for a traditional prime rib of beef method, check this link.
Prime Rib Photo (c) John Mitzewich