expected value vs arithmetic mean

expected value and arithmetic mean both are nouns.

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

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

Other synonyms of expected value include expectation, first moment.

expected value (noun)	arithmetic mean (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