According to two recent studies, it would seem that even many medical professionals fail to properly administer CPR. Here's the lowdown (you may have to save my life someday so pay attention):
Guidelines for chest compressions call for 100 to 120 compressions per minute, with a depth of about 1 1/2 inches. For ventilation, the guidelines call for two breaths for every 15 compressions before an air tube is inserted and 10 to 12 per minute after intubation.
2 for every 15. got it.