The intrinsic carrier concentration $$
\text { of a germanium sample }
$$
is $2.4 \times 10^{14} / \mathrm{m}^{3}$ at $300 \mathrm{~K}$. Its electron and hole mobilities are $0.39$ and $0.19$ $\mathrm{m}^{2} \mathrm{~V}^{-1} \mathrm{~s}^{-1}$ respectively. Calculate the conductivity of the sample.