Considering it's spherical format, the approximate volume of the model of planet earth is of 113 ft³.
What is the volume of a sphere?
The volume of a sphere of radius r is given by:
[tex]V = \frac{4\pi r^3}{3}[/tex]
In this problem, the radius is of r = 3 ft, hence the volume in cubic feet is of:
[tex]V = \frac{4\pi 3^3}{3} = 36\pi = 113[/tex]
The approximate volume of the model of planet earth is of 113 ft³.
More can be learned about the volume of a sphere at https://brainly.com/question/25608353
