Answer
$3.7\times10^{-2}$
Work Step by Step
The apparent brightness of a light source is inversely proportional to the observer’s distance from the light source, as shown in equation 33–1.
Jupiter is 5.2 times farther from the sun than Earth is, so the observed brightness of the sun is $\frac{1}{5.2^2}=3.7\times10^{-2}$, compared to the observed brightness of the sun as seen from Earth.