Pretend galaxies are evenly spaced 2.5 Mpc apart and the average mass of a galaxy is 1011 solar masses. What is the average density of matter in the universe? Suppose that the space may be represented as the set of spheres with the diameter equal to the distance between the galaxies, and each galaxy corresponds to one sphere. Hint, use the formula for volume of a sphere and the mass of the Sun is 2×1030 kg. Express your answer in units of kg/m3.