Arithmetic nruab nrab yog tus nqi feem ntau siv rau hauv kev txheeb cais, uas yog xam raws li nruab nrab xam ntawm nruab nrab ntawm cov nqi.
Yog tias peb muaj qee yam txheej
n
qhov tseem ceeb. Cia peb hu lawv
x1, x2, …, xn.
Kom tau txais qhov nruab nrab, ntxiv tag nrho
xi
thiab faib qhov tshwm sim los ntawm
n.
\(
\overline{x} = \dfrac{x_1 + x_2 + ... + x_n}{n}
\)