28.75We are asked to determine the volume of a hemisphere of diameter 28 3/4 in.
A hemisphere is half a sphere therefore, its volume is half the volume of a sphere:
Where "r" is the radius. Since the radius is half the diameter we have that:
We will convert the mixed fraction into a standard fraction using the following:
Substituting in the formula for the radius:
Now, we substitute the value of the radius in the formula for the volume:
Solving the operations:
Therefore, the volume is 6221.3 cubic inches.