Answer
$r= \dfrac{2}{3}$
Work Step by Step
The common ratio $r$ can be found by dividing a term by the previous term.
Thus, the common ratio of the given sequence is:
$\require{cancel}
r=\dfrac{\frac{8}{3}}{4}
\\r= \dfrac{8}{3(4)}
\\r= \dfrac{\cancel{8}2}{3\cancel{(4)}}
\\r= \dfrac{2}{3}$