Given arrangement, \[1/3,\text{ }1/9,\text{ }1/27,\text{ }\ldots \]

\[a\text{ }=\text{ }1/3\text{ }and\text{ }r\text{ }=\text{ }\left( 1/9 \right)/\left( 1/3 \right)\text{ }=\text{ }1/3\]

Taking the \[{{n}^{th}}\]term of this arrangement to be\[1/19683\], we have

Accordingly, the ninth term of the given succession is \[1/19683.\]