Answer
$0.025$
Work Step by Step
First, we must determine the common ratio between the terms:
$r=\frac{6}{18}=\frac{2}{6}=\frac{(\frac{2}{3})}{2}=\frac{1}{3}$
For solving this, we will use the formula for the $nth$ term of the geometric series. $a_{n}=a_{1}\times r^{n-1}$. Then put correct value for $7th$ term to solve.
$a_{7}=18 \times (\frac{1}{3})^{7-1}=0.025$
