A cylindrical column is partially filled with three liquids: water, mercury, and n-octane. The liquids are immiscible, and so three distinct layers are formed. Specific gravities of each liquid are located in Table B.1 in the appendix. The water layer is 10.0ft thick. The n-octane layer is 1.50m thick. The mercury layer thickness is 40.0cm. The column is closed and the headspace is pressurized. A pressure gauge at the bottom of the column reads 30.0 jsi. What is the absolute pressure of the headspace in mmHg ? You must include a fully labeled diagram with units as appropriate