An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

Statistics: Same as → mathematical expectation, → expected value.

From L. expectare "to await, hope," from → ex- "thoroughly" + spectare "to look," from → specere "to look at," → -scope.

Bayusesš, verbal noun of bayusidan "to expect;" Mid.Pers. pyws- "to hope for, desire" (prefixed *pati-); O.Pers. vasiy "at will, greatly, utterly," vašna- "will, favor;" Av. vas- "to will, desire, wish, long for," vasəmi "I wish," vasna- "will, favor," ušti- "desire, wish, will," vasô, vasə "at one's will." This word is extant in several Mod.Pers. dialects, Tabari vessen "to wish, desire," Gilaki vâssan "to wish, desire," vâsti "desire," Kurd. wistin "to desire, wish," Lâri avessa "to desire," colloquial Tehrâni vâsé "for" (Mid.Pers. vasnâd "because"); cf. Skt. vaś- "to wish, want, desire," váśa- "wish, desire," vasēna "for, because;" Gk. ekon "voluntary;" PIE base *uek- "to wish."

In probability and statistics, of a random variable, the summation or integration, over all values of the random variable, of the product of the value and its probability of occurrence. Also called → expectation, → expected value.

→ mathematical; → expectation.