extrapolation vs ratiocination

extrapolation

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

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

  • The diametric opposite of interpolation. 

ratiocination

noun
  • Reasoning, conscious deliberate inference; the activity or process of reasoning. 

  • Thought or reasoning that is exact, valid and rational. 

  • A proposition arrived at by such thought. 

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