Answer
Yes the terms can be part of a geometric sequence. The common ratio is $\frac{1}{2}$
Work Step by Step
The terms are 3, $\frac{3}{2}$, $\frac{3}{4}$, $\frac{3}{8}$ Since each term is multiplied by $\frac{1}{2}$ (the common ratio) to get to the next term, the sequence can be part of an arithmetic sequence.