Answer
$Z = 422~\Omega$
Work Step by Step
In part (a), we found that $X_C = 16.6~\Omega$
We can find $X_L$:
$X_L = \omega_d~L$
$X_L = 2\pi~f_d~L$
$X_L = (2\pi)(400~Hz)(0.150~H)$
$X_L = 377~\Omega$
We can find the impedance $Z$:
$Z = \sqrt{R^2+(X_L-X_C)^2}$
$Z = \sqrt{(220~\Omega)^2+(377~\Omega-16.6~\Omega)^2}$
$Z = 422~\Omega$
