The best way to prepare a prime rib is to bake it, not broil it. Broiling prime rib may cause it to lose moisture and cause the meat to become tough.
It is best to let the prime rib sit until it is at room temperature and then bake it at 425 degrees Fahrenheit for 15 minutes. After the first 15 minutes are up, decrease the temperature to 325 F for two hours and 45 minutes to help the meat lock in more moisture. This makes the prime rib juicy and tender, since the meat was seared for only a short period of time instead of being cooked at a high heat continually.