Answer :
Check the picture below.
[tex]\qquad \qquad \textit{inverse proportional variation} \\\\ \textit{\underline{y} varies inversely with \underline{x}} ~\hspace{6em} \stackrel{\textit{constant of variation}}{y=\cfrac{\stackrel{\downarrow }{k}}{x}~\hfill } \\\\ \textit{\underline{x} varies inversely with }\underline{z^5} ~\hspace{5.5em} \stackrel{\textit{constant of variation}}{x=\cfrac{\stackrel{\downarrow }{k}}{z^5}~\hfill } \\\\[-0.35em] ~\dotfill[/tex]
[tex]\stackrel{\textit{"F" inversely proportional with }"d^2"}{ {\large \begin{array}{llll} F=\cfrac{k}{d^2} \end{array}}} ~~ \textit{we also know} \begin{cases} F=228\\ d=4000 \end{cases} \implies 228=\cfrac{k}{4000^2} \\\\\\ 228(4000^2)=k\implies 3648000000=k~\hfill \boxed{F=\cfrac{3648000000}{d^2}} \\\\\\ \textit{when d = 200, what is "F"?}\qquad F=\cfrac{3648000000}{4200^2}\implies F\approx 206.8~lbs[/tex]