Calculate the mean distance between intelligent communicating civilizations in our galaxy within the galactic habitable zone, based on the following parameters. i) Spherical regions of influence. (assume adjoining regions are at right-angles) ii) Cubic regions of influence.

Some Useful Information:

Number of intelligent communicating civilizations in our galaxy: 762,000.

Diameter of Milky Way galaxy: 100,000 ly.

Location of galactic habitable zone: an annulus of 4-10 kpc from the centre of the galaxy (green region).

Average thickness of galactic disk across galactic habitable zone: 2500 ly.

1 parsec (pc) = 3.26 lightyears (ly).