Final answer:
A common standard for the minimum thickness of a concrete slab-on-ground floor is 4 inches, although this can vary depending on local codes and the intended use of the structure.
Step-by-step explanation:
The question refers to construction standards for a concrete slab-on-ground floor, which is typically an engineering concern. In general, the thickness of a concrete slab-on-ground floor should be designed to accommodate the expected loads and use cases it will face. However, for residential construction, a common standard is that concrete slabs should be a minimum of 4 inches thick. This standard can vary based on codes and regulations in different localities, as well as the intended use of the structure. For instance, for garages or areas where heavier loads are expected, the slab might need to be thicker.