Answer
About $97.7 \%$
Work Step by Step
The wavelength of blue light is $\lambda=475 \mathrm{~nm}$, and its absorption coefficient is $\mu(475)=0.000114$. We have
$\begin{aligned} T_\lambda(200) & =e^{-\mu(475) \cdot 200} \\ & =e^{-0.000114(200)} \\ & =0.97746,\end{aligned}$
About $97.7 \%$ of blue light is transmitted.
