Thermodynamics, Linear Interpolation

[CursedAntagonis]

Homework Statement

I have been trying to learn how to use linear interpolation to find out the data needed from the thermodynamics chart, however, the book that is assigned does not even talk about it. Could someone please explain how linear interpolation is used? Thanks

 

[hotvette]

The assumption with linear interpolation is that the two points (x₁, y₁) and (x₂, y₂) are connected with a line. Using the two point equation of a line, we get:

y - y₁ = m (x - x₁), where m = (y₂ - y₁)/(x₂ - x₁)

Thus for x₃ that is between x₁ and x₂, we get:

y₃ = y₁ + (x₃ - x₁) (y₂ - y₁)/(x₂ - x₁)