Question 935740
formula for circumference of the sphere = 4/3 * pi * r^3
formula for the area of the sphere is equal to 4 * pi * r^2
formula for the circumference of the sphere is equal to 2 * pi * r


circumference divided by volume is equal to (2 * pi * r) / (4/3 * pi * r^3) which simplifies to 3 / (2 * r^2).

the change is not constant per unit of r.


the volume of the sphere divided by its circumference is equal to (4/3 * pi * r^3) / (2 * pi * r) which simplifies to (2 * r^2) / 3.


the change is not constant per unit of r.


The area of the sphere divided by its volume is equal to (4 * pi * r^2) / (4/3 * pi * r^3) which simplifies to 3 / r.


the change is not constant per unit of r.


the volume of the sphere divided by its area is aequal to (4/3 * pi * r^3) / (4 * pi * r^2) which simplifies to r / 3.


this change is constant per unit change of r.


when r = 1, the ratio is 1/3.
when r = 2, the ratio is 2/3.
when r = 3, the ratio if 3/3.
when r = 4, the ratio is 4/3.


the ratio changes by 1/3 for every unit change in r.


selection D is your answer.