Answer
True.
Work Step by Step
The general formula for finding ${{a}_{n}}$ is given by;
${{a}_{n}}\text{ }={{a}_{1}}\text{ }{{\left( r \right)}^{n-1}}$
Here, $r$ is the common ratio.
Compare the equation with ${{a}_{n}}\text{ }=\text{ }3{{\left( 0.5 \right)}^{n-1}}$.
We get
$r=\frac{1}{2}$
Hence, the given statement is true.