Interpolation and Extrapolation:

Chapter Interpolation and extrapolation  covers  the  use  of  interpolation  and  extrapolation  to  solve  for unknowns on various types of graphs.

Given a graph, SOLVE for the unknown using extrapolation.

Given a graph, SOLVE for the unknown using interpolation.

Definitions

Interpolation: Interpolation is the procedure of acquiring a value from a graph or table that is located among major points given, or among data points plotted. A ratio process is commonly used to obtain the value.

Extrapolation: Extrapolation is the procedure of acquiring a value from a chart or graph which extends beyond the given data.  The trend of the data is extended past the last point given and an estimate made of the value.