arithmetic mean vs expected value

arithmetic mean and expected value both are nouns.

Word	Noun	Adjective	Verb	Adverb
arithmetic mean	Yes	No	No	No
expected value	Yes	No	No	No

As nouns, arithmetic mean and expected value are synonyms defined as:

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

Other synonyms of arithmetic mean include expectation, first moment.

arithmetic mean (noun)	expected value (noun)
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