Answer:
The difference in volume of the two models is [tex]\frac{128}{3}\ in^{3}[/tex]
Step-by-step explanation:
we know that
The volume of a square pyramid is equal to
[tex]V=\frac{1}{3}b^{2}h[/tex]
where
b is the length of the side of the square base
h is the height of the pyramid
step 1
Find the volume of Amy's model
we have
[tex]b=8\ in[/tex]
[tex]h=5\ in[/tex]
substitute
[tex]V=\frac{1}{3}(8)^{2}(5)[/tex]
[tex]V=\frac{320}{3}\ in^{3}[/tex]
step 2
Find the volume of Alex's model
we have
[tex]b=8\ in[/tex]
[tex]h=3\ in[/tex]
substitute
[tex]V=\frac{1}{3}(8)^{2}(3)[/tex]
[tex]V=\frac{192}{3}\ in^{3}[/tex]
step 3
Find the difference in volume of the two models
[tex]\frac{320}{3}\ in^{3}-\frac{192}{3}\ in^{3}=\frac{128}{3}\ in^{3}[/tex]