estimation vs extrapolation

estimation

noun
  • The process of making an estimate. 

  • The amount, extent, position, size, or value reached in an estimate. 

  • Esteem or favourable regard. 

extrapolation

noun
  • A calculation of an estimate of the value of some function outside the range of known values. 

  • The diametric opposite of interpolation. 

  • An inference about some hypothetical situation based on known facts. 

How often have the words estimation and extrapolation occurred in a corpus of books? (source: Google Ngram Viewer )