Answer
The cost of carpeting is\[\$556.50\].
Work Step by Step
To find the cost of carpeting the rectangular floor, we need to find the area of the floor (in square yards) and multiply it with the cost per square yard.
As we know that\[1\text{ ft}=\frac{1}{3}\text{yd}\], compute the given area in yards as mentioned below:
\[\begin{align}
& 21\text{ ft}=\text{21 ft}\times \frac{1\text{ yd}}{3\text{ ft}} \\
& =7\text{ yd}
\end{align}\]
Therefore, the area of the rectangular floor (in square yards) will be as follows:
\[\begin{align}
& A=lw \\
& =3\text{ yd}\times 7\text{ yd} \\
& =21\text{ y}{{\text{d}}^{2}}
\end{align}\]
The floor cost of carpeting is $26.50 per square yard.
Compute the cost of carpeting (denoted by C) of the floor as follows:
\[\begin{align}
& C=A\times \$26.50\\&=21\text{y}{{\text{d}}^{2}}\times\text{}\!\!\$\!\!\text{}26.50\\&=\$556.5\end{align}\]
Hence, the cost to carpet of the rectangular floor is\[\$556.50\].
