Answer
4.39 atm
Work Step by Step
Use the ideal gas model. The amount of gas, n, is constant. The value of PV/T remains constant.
$$\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}$$
$$P_2=P_1\frac{V_1}{V_2}\frac{T_2}{T_1}$$
$$P_2=(2.45atm)\frac{61.5L}{38.8L}\frac{273.15+56.0K}{273.15+18.0K}=4.39atm$$