Final answer:
A Ground Fault Circuit Interrupter (GFCI) installed on an ungrounded circuit with ground type receptacles significantly improves system safety by promptly interrupting fault currents.
Step-by-step explanation:
Installing a Ground Fault Circuit Interrupter (GFCI) on an ungrounded circuit with ground type receptacles will improve the safety of the system. The GFCI enhances electrical safety by detecting and interrupting fault currents, preventing shock hazards, especially in environments where water is present which provides a conductive path for electricity. The three-wire system which includes a live/hot, neutral, and earth/ground wire provides additional safety by ensuring that any fault is quickly detected and the circuit breaker trips, necessitating the repair of the faulty appliance. This safety system is essential in settings like kitchens, where the risk of electrical shock is increased due to potential water contact.