Volume of a sphere is
Vbask=4/3 pi (rₐ)^3 where rₐ is the radius of a basketball
v tenn= 4/3 pi (rₓ)^3 where rₓ is the radius of the tennis ball
we know that rₐ=3.6 rₓ
vbasket/v tennis= 4/3pi (3.6 rₓ)^3= we see all is cancelled beside
4/3 pi rₓ
3.6^3=46.65
the volume of the basketball is aprox 46.65 bigger than the volume of the tennis ball