ANSWER
![\operatorname{\$}192.51]()
Step-by-step explanation
First, we have to find the area of the rectangular floor by applying the formula for the area of a rectangle:
![A=L*W](https://img.qammunity.org/2023/formulas/mathematics/college/ey9bmb7cs83djpdrh9iksx1h68us9742dv.png)
where L = length
W = width
Therefore, the area of the rectangle is:
![\begin{gathered} A=9*15.5 \\ A=139.5\text{ }ft^2 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/vglf5ee18zedbbnh9ah8wt3no14vk3qh33.png)
Now, find the cost by finding the product of the area of the floor and the cost per unit area:
![\begin{gathered} 139.5*1.38 \\ \$192.51 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/3fwq12um6g3n8t0nggsp4nz2mansadoczp.png)
That is the answer.