extrapolation vs prognosis

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. 

prognosis

noun
  • A forecast of the future course or outcome of a situation based on what is presently known; a prediction. 

  • A forecast of the future course or outcome of a disease or disorder based on current medical knowledge. 

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