Find the four numbers forming a G.P. in which the $3^{rd}$ term is greater than the $1^{st}$ term by $9$ and the $2^{nd}$ term is greater than the $4^{th}$ term by $18$.

Question

$\begin{array}{1 1}3,-9,27,-81 \\ 2,-6,18,-54 \\ 3,6,12,24 \\ 3,-6,12,-24 \end{array}$