First, we need to calculate the volume of the original hemisphere. The formula for the volume of a hemisphere is V = (2/3)Ļr^3.
Plugging in the radius of 20 inches, we get:
V1 = (2/3) * 3.14 * 20^3
V1 = (2/3) * 3.14 * 8000
V1 = 0.66667 * 25120
V1 = 16746.72
Now, we need to calculate the volume of the removed hemisphere. The formula for the volume of a hemisphere is the same, V = (2/3)Ļr^3.
Plugging in the radius of 15 inches, we get:
V2 = (2/3) * 3.14 * 15^3
V2 = (2/3) * 3.14 * 3375
V2 = 0.66667 * 10642.5
V2 = 7095
To find the volume of the sculpture, we subtract V2 from V1:
V = V1 - V2
V = 16746.72 - 7095
V = 9651.72
We round this to the nearest whole number:
Vā 9652
Therefore, the volume of his sculpture is approximately 9652 cubic inches.