Answer:
2.598740044 * 10^11.
That is as accurate as my calculator can be.
Step-by-step explanation:
The radius = 1/2 diameter = 1/2 * 7917.5
= 3958.7m miles.
The volume of a sphere is 4/3 π r^3 so:
Volume of the Earth = 4/3 π 3958.7^3
= 2.598740044 * 10^11.