can you work out the math completely for the example calculation: At 2820 ft: Observed Transit Time (tt): 158 sec/ft Normal Transit Time (tntn): Assume around 100 sec/ft Normal Pressure Gradient: 0.465 psi/ft Overburden Pressure: Assume 1 psi/ft Calculate Pore Pressure: Pp=0.465+(10.465)(100158)3 Pp=0.465+(10.465)(158100)3 Convert to Equivalent Density: Equivalent Density=Pp0.0522820 Equivalent Density=0.0522820Pp This should give you a value close to 8.942308 pp