Answer
$a_n=6 (3)^{n-1}$
Work Step by Step
The nth term is given by $a_n= a_1 r^{n-1}$ ...(1)
Here, we have $162=a_1 r^3$
and $4374=(162/r^3) (r^6/1) \implies r=3$
$a_1=\dfrac{162}{(3)^3} \implies a_1=6$
Equation (1) becomes: $a_n=6 (3)^{n-1}$
Hence, $a_n=6 (3)^{n-1}$
