Average

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Dina matematik, aya loba metoda keur ngitung average atawa central tendency tina hiji susunan n data. Metoda anu umum dipake, jeung geus umum dijadikeun acuan keur ngitung the average, nyaeta arithmetic mean. Bisa dilongok table of mathematical symbols keur nerangkeun simbol anu digunakeun.

[édit] Aritmetik Mean

Arithmetic mean nyaeta standar "average", biasa dipake keur nyebut "mean". It is used for many purposes and may be abused by using it to describe skewed distributions, with highly misleading results. A classic example is average income. The arithmetic mean may be used to imply that most people's incomes are higher than is in fact the case. When presented with an "average" one may be led to believe that most people's incomes are near this number. This "average" (arithmetic mean) income is higher than most people's incomes, because high income outliers skew the result higher (in contrast, the median income "resists" such skew). However, this "average" says nothing about the number of people near the median income (nor does it say anything about the modal income that most people are near). Nevertheless, because one might carelessly relate "average" and "most people" one might incorrectly assume that most people's incomes would be higher (nearer this inflated "average") than they are. Consider the scores {1, 2, 2, 2, 3, 9}. The arithmetic mean is 3.17, but five out of six scores are below this!

$\bar{x} = {1 \over n} \sum_{i=1}^n{x_i}$

[édit] Median

Median nyaeta nilai sahandapeun 50% tina skor nu aya, atawa nilai tengah. Dina kaayaan skor genap, mangka median ngarupakeun nilai rata-rata tina dua nilai tengah eta. Penting dipake keur "ke-pencong-an" sebaran, nu ngagambarkeun leuwih akurat tinimabng rata-rata aritmetik. (Tempo data {1, 2, 2, 2, 3, 9} bandingkeun: median nu sarua jeung 2, dina kasus ieu, leuwih nembongkeun central tendency tinimbang rata-rata aritmetik nu sarua jeung 3.16.)

[édit] Mode

The Mode is simply the most frequent score. It is most useful where the scores are not numeric: for example, while the mode {1, 2, 2, 2, 3, 9} is 2, the mode of {apple, apple, banana, orange, orange, orange, peach} is orange.

[édit] Other averages

The geometric mean, harmonic mean, generalized mean, weighted mean, truncated mean, and interquartile mean are described in their own articles and in the Mean article.