First we must remember that the unit for pressure is usually written in SI units, and we have to convert all the given parameters to metric units. Given are height h=59mm convert this to "meter" just simply divide 59 to 1000. Next is Pressure equal to P=771mmhg(at 0 degrees Celsius), convert this to "Pascal" or Newton per square meter (N/m2). The standard atmospheric pressure is equivalent to 101,325Pa. This represents the force of pressure of the atmosphere pressing on our body. The density of air is equivalent to 1.225kg/m3. Now, write first all the given, h=( ? ) P2=101,325Pa, Density of Air Da=1.225kg/m3. The normal pull of gravity g = 9.8m/s2. Unknown Pressure is P1=? . Then follow this formula (P1 = P2 + Dgh).