expectation vs arithmetic mean

expectation and arithmetic mean both are nouns.

Word	Noun	Adjective	Verb	Adverb
expectation	Yes	No	No	No
arithmetic mean	Yes	No	No	No

As nouns, expectation and arithmetic mean are synonyms defined as:

expectation and arithmetic mean: the sum of the values of a random variable divided by the number of values

Other synonyms of expectation include expected value, first moment.

expectation (noun)	arithmetic mean (noun)
belief about (or mental picture of) the future	the sum of the values of a random variable divided by the number of values
the sum of the values of a random variable divided by the number of values
the feeling that something is about to happen
anticipating with confidence of fulfillment