we have that
the radius is
r=12.1 in
the volume of a sphere is
[tex]V=\frac{4}{3}\cdot\pi\cdot r^3[/tex]substitute the given values
[tex]\begin{gathered} V=\frac{4}{3}\cdot3.14\cdot12.1^3 \\ \\ V=7,416.94\text{ in3} \end{gathered}[/tex]Part 2
In this problem we have the diameter of the sphere
D=13.6 mm
so
r=D/2=13.6/2=6.8 in
substitute in the formula
[tex]\begin{gathered} V=\frac{4}{3}\cdot3.14\cdot6.8^3 \\ V=1,316.42\text{ in3} \end{gathered}[/tex]