Answer
$f_e=8.5cm$
$\theta=6.21\times10^{-6}rad$
$r=2.4km$
Work Step by Step
$f_e=f_o\frac{d_o}{l}\frac{N}{d}=(2.0m)\frac{6.5km}{384,000km}\frac{250mm}{0.10mm}=8.5cm$
$\theta=1.22\frac{\gamma}{D}=1.22\frac{560\times10^{-9}m}{0.11m}=6.21\times10^{-6}rad$
$r=(384,000km)(6.21\times10^{-6}rad)=2.4km$