Pressure is typically calculated by interpolation using the equation:

P = P1 + (P2 – P1) * ((X – X1) / (X2 – X1))

Where:

• P is the pressure at a desired point
• P1 and P2 are the pressure values at two known points
• X is the variable of interest (e.g., temperature, altitude, depth)
• X1 and X2 are the values of the variable at the two known points

Interpolation involves estimating the value of P at a point X that lies between two known points (X1 and X2) by linearly scaling the difference in pressure between the two known points based on the relative difference between the variable values (X – X1) / (X2 – X1).

This equation assumes a linear relationship between pressure and the variable of interest and assumes that the data points are evenly spaced.