Answer:
[tex]\boxed{\text{54 ft}}[/tex]
Step-by-step explanation:
We can use ratio and proportion to solve this problem.
Let l = the length
and w = the width = 24
[tex]\begin{array}{rcll}\dfrac{l}{24} & = & \dfrac{9}{4} & \\\\l & = & \dfrac{9\times24}{4} &\text{Multiplied each side by 24} \\\\l & = & 9 \times 6 & \text{Divided by 4}\\ & = &\mathbf{54} & \text{Simplified}\\\end{array}\\\text{The pool should be $\large \boxed{\textbf{54 ft}}$ long}[/tex]
Check:
[tex]\begin{array}{rcl}\dfrac{54}{24} & = &\dfrac{9}{4} \\\\\dfrac{9}{4} & = & \dfrac{9}{4} \\\end{array}[/tex]
