If it is required to use a single number as a "typical" value for a set of known numbers , then the arithmetic mean of the numbers does this best since it minimizes the sum of squared deviations from the typical value: the sum of .
ɪf ɪɾ ɪz ɹᵻkwˈaɪɚd tə jˈuːz ɐ sˈɪŋɡəl nˈʌmbɚɹ æz ˈeɪ "tˈɪpɪkəl" vˈæljuː fɚɹə sˈɛt ʌv nˈoʊn nˈʌmbɚz , ðˈɛn ðɪ ɚɹˈɪθmətˌɪk mˈiːn ʌvðə nˈʌmbɚz dˈʌz ðɪs bˈɛst sˈɪns ɪt mˈɪnɪmˌaɪzᵻz ðə sˈʌm ʌv skwˈɛɹd dˌiːvɪˈeɪʃənz fɹʌmðə tˈɪpɪkəl vˈæljuː: ðə sˈʌm ʌv .