extrapolation vs forecast

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. 

forecast

noun
  • An estimation of a future condition. 

  • exacta 

  • A prediction of the weather. 

verb
  • To estimate how something will be in the future. 

  • To foreshadow; to suggest something in advance. 

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