Answer:
0.07708 g/cm³
Step-by-step explanation:
Density describes the mass per volume of a substance.
Volume
Density is the mass per volume, so we need to find the volume of the object. For a sphere, the volume formula is:
In this equation, r is the radius of the sphere. So, we can plug in 2.9 for r and solve.

- V ≈ 102.16 cm³
When rounded to 2 decimal points, the volume of the object is 102.16 cm³.
Density
Now that we know the volume, we can find the density. The density formula is:
In this equation, m is the mass and V is the volume. So, we can plug in the mass, 7.875g, and the volume, 102.16 cm³.

- D = 0.07708
When rounded to 4 significant figures, the density of the object is 0.07708 grams per centimeter cubed.