Final answer:
The UAP was using the correct CPR procedure by depressing the sternum at least 5 cm (2 inches) deep during chest compressions.
Step-by-step explanation:
The nurse determined that the unlicensed assistive person (UAP) was using the correct procedure when performing CPR on an adult client by noting that the sternum was being depressed at least 5 cm, which is approximately 2 inches. This is in accordance with current standards for CPR, which require chest compressions to be at least 5 cm deep at a rate of 100 compressions per minute. It's also important to note that compressions should be performed between the T4 and T9 vertebrae to effectively circulate blood and minimize the risk of injury to the patient.