Answer
a) $20$ pounds
b) $19$ months
Work Step by Step
Given \begin{equation}
W(m)=9.3 \sqrt[3]{m}.
\end{equation} A) Find $W(10)$:
\begin{equation}
\begin{aligned}
W(10)&=9.3 \sqrt[3]{10}\\
&\approx 20.0.
\end{aligned}
\end{equation} The average weight of baby girls who are $10$ months old is about $20$ pounds.
B) Solve for $m$ by setting $W(m) = 25$: \begin{equation}
\begin{aligned}
9.3 \sqrt[3]{m}&=25\\
(\sqrt[3]{m})^3&=\left( \frac{25}{9.3}\right)^3\\
m&\approx 19.
\end{aligned}
\end{equation} The average age of baby girls who weigh $25$ pounds are about $19$ months old.
