Answer:
V ≈ 16.333 in³
Step-by-step explanation:
Formula of the Volume of a Sphere: 
V =
× (3.5)²π
V =
× 12.25π
V ≈ 16.333 in³
The 7th day is going to be 15.6 there is a common scale factor of timing by 2 the difference between the days so you would get 15.6
i am not very good it math but i thing is B so yeah bye.