Answer :
The cost of the paint needed to give the entire wall a good coverage of paint is $22
Firstly, we need to calculate the equivalent areas
Mathematically, we know that 1 ft is 12 inches
So to calculate the area of the wall in square inches, we have;
[tex]8\times22\times12\times\text{ 12 = 25,344 sq. inches}[/tex]Now let us calculate the area of the test;
We have this as;
[tex]14\times\text{ 18 = 252 sq.inches}[/tex]Now, we know that1 ounce is okay for the test, the number of ounces okay for the main wall would be;
[tex]\frac{25,344}{252}\text{ }\times\text{ 1 ounce =100.60 ounces}[/tex]So, 100.60 ounces of paint would be enough to cover the wall
Finally, we proceed to get the cost of this as follows;
Mathematically, 1 ounce is 0.0078125 gallons
So, the number of ounces would be;
[tex]100.60\times0.0078125\text{ = 0.786 gallons}[/tex]From the question, the cost per gallon is $28
So, the cost in 0.786 gallons would be;
[tex]0.786\times28\text{ = \$22}[/tex]