Answer:
Greater than.
Step-by-step explanation:
As per the question, if a glass filled with air is held upside down and taken to the swimming pool's bottom without tipping it; the thickness of the air within the glass would be 'greater than' in comparison to the surface due to the air density physics. It states that the density of air is influenced by the pressure as well as the temperature of the environment and thus, the higher pressure at the bottom of the swimming pool would make the air denser than the surface. Therefore, the inner density would be 'greater than' as on the surface.