Answer
(a)
The median height of girls who are $50$ months old is approximately $41\text{ inches}$.
From the graph, check for the value of $y\text{-axis}$ for the corresponding value on $x\text{-axis}$as $50$.
As shown by the line, it is $41\text{ inches}$.
(b)
Consider the provided formula,
$h=3.1\sqrt{x}+19$
Substitute $50$ for $x$ and find $h$.
That is.,
$h=3.1\sqrt{50}+19$
Now, use a calculator to find the value.
So, the value of $h$is $40.9\text{ inches}$, which is close to $41$ as calculated above.
