The series impendance matrix of a short three-phase transmission line in phase coordinates is $\left[\begin{array}{ccc}{Z}_s& Z_m& Z_m\\ Z_m& Z_s& Z_m\\ Z_m& Z_m& Z_s\end{array}\right]$. If the positive sequence impedance is (1 + j10)$\Omega$, and the zero sequence impedance is (4 + j31)$\Omega$, then the imaginary part of Z${}_m$(in $\Omega$) is (upto to 2 decimal places).

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