ANSWER :
$304.50
EXPLANATION :
From the problem, we have a pool table with dimensions of 3 foot by 7 foot.
The area of the table is :
[tex]3ft\times7ft=21ft^2[/tex]The cost of the table is $14.50 per square foot.
So the cost of the table will be :
[tex]21\cancel{ft^2}\times\frac{\$14.50}{1\cancel{ft^2}}=\$304.50[/tex]