The mass of zinc produced by the electrolysis of zinc sulphate solution with a steady current of \( 0.015 \, \mathrm{A} \) for \( 15 \) minutes is __________ \( \times 10^{-4} \, \mathrm{g} \). (Atomic mass of zinc \( = 65.4 \, \mathrm{amu} \))