use 1.9 as the radius for the sphere and answer the following
1-volume =
2-surface area=
3-ratio of the volume to surface area=
remember everything is with the sphere and radius 1.9 you have to use them to answer the volume, surface area, ratio of the volume to surface area
Volume = (4/3)π (1.9)^3 = 28.7309...
SA = 4π (1.9)^2 = 45.36459...
ratio of V : SA = 28.7309.../45.36459...
= .63333...
in general , ratio of volume/SA
= (4/3)πr^3/(4πr^2)
= (1/3) r
using our values above
ratio vol. / SA
= (4/3)π(1.9)^3 / (4π (1.9)^2)
= (1/3)(1.9)
= 19/30
= .63333... , same as above