Final answer:
The ambient temperature correction factor for a THW-2 wire at 120 degrees F ambient depends on the manufacturer's data.
Step-by-step explanation:
The ambient temperature correction factor is used to compensate for changes in the resistance of a wire due to variations in temperature. In order to calculate the correction factor for a THW-2 wire at 120 degrees F ambient, you would need to know the resistance vs. temperature characteristics of the wire. This information is typically provided by the manufacturer.
Without the specific resistance vs. temperature data for the THW-2 wire, it is not possible to determine the ambient temperature correction factor at 120 degrees F ambient. It is best to consult the manufacturer's documentation or contact a technical expert in the field for accurate information.