extrapolate vs interpolate

extrapolate and interpolate both are verbs.

Word	Noun	Adjective	Verb	Adverb
extrapolate	No	No	Yes	No
interpolate	No	No	Yes	No

As verbs, extrapolate and interpolate are synonyms defined as:

extrapolate and interpolate: estimate the value of something based on known values

extrapolate (verb)	interpolate (verb)
estimate the value of something based on known values	insert words into texts, often falsifying it thereby
gain knowledge of (an area not known or experienced) by extrapolating	estimate the value of something based on known values
draw from specific cases for more general cases