The positive, negative, and zero sequence reactances of a wye-connected synchronous generator are $0.2$pu, $0.2$pu, and $0.1$pu, respectively. The generator is an open circuit with a terminal voltage of $1$pu. The minimum value of the inductive reactance, in pu, required to be connected between neutral and ground so that the fault current does not exceed $3.75$pu if a single line to ground fault occurs at the terminals is ___________ (assume fault impedance to be zero). (Give the answer up to one decimal place.)