The figure shows a circuit of four resistors that are connected to a larger circuit. The graph below the circuit shows the electric potential V(x) as a function of position x along the lower branch of the circuit, through resistor 4; the potential VA is 10.8 V. The graph above the circuit shows the electric potential V(x) versus position x along the upper branch of the circuit, through resistors 1, 2, and 3; the potential differences are ΔVB = 1.56 V and ΔVC = 4.77 V. Resistor 3 has a resistance of 220 Ω. What is the resistance of resistor 1?