Answer
The common ratio is $r=-8$.
Work Step by Step
The given sequence is
$\frac{3}{8},-3,24,-192,...$
Calculate the ratio between each pair of consecutive terms.
$\frac{-3}{3/8}=-8$
$\frac{24}{-3}=-8$
$\frac{-192}{24}=-8$
Hence, the common ratio is $r=-8$.
