Answer
$32.39$ astronomical units (which is $\approx 3013$ million miles)
Work Step by Step
We have $ r=\dfrac{1.069}{1+0.967 \sin \theta}$
or, $ r=\dfrac{1.069}{1+0.967 \sin (\dfrac{3 \pi}{2})}$
(we use $\theta=\dfrac{3\pi}{2}$ for the maximum distance from the sun.)
or, $ r \approx 32.39$ astronomical units
