Answer:
The volume of a pyramid with a square base can be found using the formula:
V = (1/3)Bh
where B is the area of the base and h is the height of the pyramid.
In this problem, we are given that the perimeter of the base is 10.4 in, which means that each side of the square base has a length of 10.4 in / 4 = 2.6 in. Therefore, the area of the base is:
B = (2.6 in)^2 = 6.76 square inches
We are also given that the height of the pyramid is 9.6 in.
Substituting these values into the formula for the volume of a pyramid, we get:
V = (1/3)(6.76 sq in)(9.6 in)
V = 20.416 cubic inches
Rounding to the nearest tenth of a cubic inch, the volume of the pyramid is approximately 20.4 cubic inches.