Final answer:
For CPR compressions, adults require a depth of 5 cm, children 1 to puberty also require 5 cm, while infants under 1 year require about 4 cm in depth.
Step-by-step explanation:
The required depths of compressions for cardiopulmonary resuscitation (CPR) differ by age group. For adults, the standard is to compress the chest at least 5 cm deep at a rate of 100 compressions per minute. For children aged 1 to puberty, it is recommended to compress at least one third the depth of the chest, approximately 5 cm. For infants (under 1 year), the recommendation is also one third the depth of the chest, which is usually about 4 cm. It is essential to perform these compressions with high quality to ensure the blood is sufficiently circulated throughout the body, which is particularly crucial for the brain.