Answer:
Cost in decreasing order: Project B>Project A>Project D>Project C
Step-by-step explanation:
Project A
Area: [tex]A=20 in*15 in= 300 in^2[/tex]
Scale: [tex]S=\frac{4 ft *4ft}{1 in*1in}=16 \frac{ft^2}{in^2}[/tex]
Cost:
[tex]C=\frac{22000}{300 in^2*16 \frac{ft^2}{in^2}}[/tex]
[tex]C=\frac{4.58}{ft^2}[/tex]
Project B
Area: [tex]A=10 in*8 in= 80 in^2[/tex]
Scale: [tex]S=\frac{8 ft *8ft}{1 in*1in}=64 \frac{ft^2}{in^2}[/tex]
Cost:
[tex]C=\frac{25000}{80 in^2*64 \frac{ft^2}{in^2}}[/tex]
[tex]C=\frac{4.88}{ft^2}[/tex]
Project C
Area: [tex]A=15 in*12 in= 180 in^2[/tex]
Scale: [tex]S=\frac{6 ft *6ft}{1 in*1in}=36 \frac{ft^2}{in^2}[/tex]
Cost:
[tex]C=\frac{27000}{180 in^2*36 \frac{ft^2}{in^2}}[/tex]
[tex]C=\frac{4.16}{ft^2}[/tex]
Project D
Area: [tex]A=8 in*6 in=48 in^2[/tex]
Scale: [tex]S=\frac{12 ft *12ft}{1 in*1in}=144 \frac{ft^2}{in^2}[/tex]
Cost:
[tex]C=\frac{30000}{48 in^2*144 \frac{ft^2}{in^2}}[/tex]
[tex]C=\frac{4.34}{ft^2}[/tex]
