Question

What is the volume of a sphere with a diameter of 2 1/2 inches

Answer 1

I think the answer is 6.5417in cubed, i am not sure

Answer 2

The formula for volume of a sphere is:

$\frac{4}{3} \pi r^{3}$ where r is the radius

Since we are not given the radius, we can just cut the diameter in half, which is the equivalent.

We should end up getting a radius of 5/4

We now need to substitude 1.25 for r
$\frac{4}{3} \pi \frac{5}{4}^{3}$ 

$\frac{4}{3} \pi 125/64$ 

We can change this to 125/64 * 4/3 * π

Simplify further to get 125/16 * 1/3 * π (cross out the 4's)

Multiply and your final volume should be 125/48π in³