Answer
The intensity is $1.36 \times 10^{-6}~W/m^2$
The average energy density is $4.53\times 10^{-15}~J/m^3$
Work Step by Step
We can find the intensity:
$I = (\frac{E_m}{\sqrt{2}})^2~c~\epsilon_0$
$I = \frac{E_m^2~c~\epsilon_0}{2}$
$I = \frac{(32.0\times 10^{-3}~V/m)^2~(3.0\times 10^8~m/s)~(8.85\times 10^{-12}~C^2/N~m^2)}{2}$
$I = 1.36 \times 10^{-6}~W/m^2$
The intensity is $1.36 \times 10^{-6}~W/m^2$
We can find the average energy density:
$U = \frac{I}{c} = \frac{1.36 \times 10^{-6}~W/m^2}{3.0\times 10^8~m/s} = 4.53\times 10^{-15}~J/m^3$
The average energy density is $4.53\times 10^{-15}~J/m^3$.
