The approximate difference in the amount of wax needed to make a candle from each mold is about 56.52 in³. The correct option is therefore the fourth option
56.52 cubic inches
The steps used to find the difference in the amount of wax needed for each mould can be presented as follows;
The volume of wax needed to make a candle from a mould is the volume of the mould
The volume of the cylindrical mould, V₁ = π·r²·h
Where π ≈ 3.14, r is the radius of the cylinder, and h is the height of the cylinder
V₁ = 3.14 × 3² × 6
3.14 × 3² × 6 = 169.56
Volume of the cylinder, V₁ = 169.56 in.³
The volume of the spherical mould, V₂ = (4/3)·π·r³
Where π ≈ 3.14, r is the radius of the sphere
V₂ = (4/3) × 3.14 × 3³
(4/3) × 3.14 × 3³ = 113.04
Volume of the cylinder, V₂ = 113.04 in.³
The difference in the amount of wax needed, V₁ - V₂, is therefore;
V₁ - V₂ = 169.56 - 113.04
169.56 - 113.04 = 56.52
The difference in the amount of wax needed is about 56.52 cubic inches