Answer
\begin{equation}
\begin{aligned}
y&= 5(0.5^{1/3})^{t}\\
&=ab^t \\
a&= 5\\
b&= 0.5^{1/3}\\
\end{aligned}
\end{equation}
Work Step by Step
Given $$y = 5(0.5)^{t/3} $$ Rearrange the function to get.
\begin{equation}
\begin{aligned}
y&= 5(0.5)^{t/3}\\
&= 5(0.5^{1/3})^{t}\\
y&=ab^t \\
a&= 5\\
b&= 0.5^{1/3}\\
\end{aligned}
\end{equation}