Step 1. Find the area of the circle.
The formula for the area of a circle is as follows:

Where pi is 3.14 and r is the radius of the circle.
The radius is half of the diameter, and since the diameter is 10 in, thus the radius is:

Substituting the radius and pi into the area formula:

Solving the operations:

Step 2. Multiply the area by the cost per square inch.
The cost per square inch is $4.50, so we multiply 78.5 by 4.50:

The total cost is $353.25
Rounding the answer to the nearest dollar: $353