Final answer:
Flexible metal conduit must be supported at intervals not greater than 4.5 feet, with variations depending on factors such as diameter and the type of supports used.
Step-by-step explanation:
The question is related to the support intervals for flexible metal conduit installation. According to the National Electrical Code (NEC), flexible metal conduit (FMC) should be supported at intervals not greater than 4.5 feet (1.4 meters). The exact spacing may vary depending on the diameter and weight of the conduit as well as the type of supports used. It's important for the conduit to be properly supported to prevent sagging and damage due to the weight of the conductors or any external force that might be applied to the conduit system.