Answer:
87.4%
Explanation:
The radius to the top of the atmosphere as a fraction of the moon's radius is ...
(2575 +600)/2575 ≈ 1.23301
The ratio of the moon's volume with atmosphere to the moon's volume without is the cube of this, or 1.87456
Then the ratio of the atmosphere's volume to the moon's volume is ...
(1.87456 -1)/1 = 0.87456
Atmospheric haze is about 87.4% of the moon's volume.
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We have assumed that the desired ratio is to the solid moon's volume, not the volume of moon and atmosphere together. The latter ratio would be 0.875 to 1.875 or about 46.7%.