Final answer:
The nurse should place the stethoscope on the left side of the sternum at the fifth intercostal space, also known as the tricuspid area, to auscultate the tricuspid valve.
Step-by-step explanation:
To auscultate the tricuspid valve, the nurse will place the stethoscope on the left side of the sternum at the fifth intercostal space. This is also known as the tricuspid area. The tricuspid valve is located between the right atrium and the right ventricle, so listening for the heart sounds in this area allows the nurse to assess the functioning of the valve.