Answer
$59975.62$ days
Work Step by Step
As per the given problem, we have:
$T^2=kd^2$
Here, $k$ is defined as constant of proportionality
Plug the given values in the above expression, we get
$(365)^2=k(93 \times 10^6)^3$
This gives $k=1.6262 \times 10^{-19}$
$T^2=(1.6262 \times 10^{-19})(2.79\times 10^{9})^3$
$\implies T=59975.62$ days