Answer:
B. 8.0 cubic inches
Step-by-step explanation:
Sphere volume is ...
V = (4/3)πr³ = (4/3)π(2 in/2)³ = 4π/3 in³ ≈ 4.19 in³
For estimation purposes, we should use a value that is 1.9 times this, or ...
estimation volume = 1.9×4.19 in³ ≈ 7.96 in³ ≈ 8.0 in³
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The factor 190% comes from the ratio 6/π ≈ 190.99%. Using this ratio means you're estimating volume as though the sphere were a cube with a side length equal to the diameter of the sphere.
A random packing of equal-size spheres (as, for example, gumballs) usually only requires a factor of about 160% to account for the empty space.