the area is
[tex]A=2\times\pi\times r^2[/tex]
the radius is 6in because is the half of diameter
now find the area
[tex]\begin{gathered} A=2\times3.14\times6^2 \\ A=226.08 \end{gathered}[/tex]
then divide the cost between the area
[tex]\frac{12.55}{226.08}=0.055[/tex]
the cost per square inch of the pie is $0.055
