An interpolation program takes two known points of a line and will produce any other point on that line given one of the components of that point.

For example:

knowing the x and y values for two points:

  x1 = 1    y1 = 3
  x2 = 5    y2 = 6

and you want to know the y value given an x value of 8

You would enter onto the stack the  x and  y  values of the two known points and then the x value of the desired point, like this:

1
3
5
6
8

Pressing SLVY produces the result for the y value:

8.25

The SLVX will of course solve for the x value if the y value is known. 

Caution:  This program is intended for linear functions only. It is not accurate for logarithmic, exponential or parabolic functions unless the points to be considered are very close to each other. This program is intended for interpolating between points that are given in a table and the value of a point somewhere in between is desired.
