Formules

Calculatrice de quartiles

Trouvez le résumé en cinq nombres d’une série — minimum, Q1, médiane, Q3 et maximum — ainsi que l’écart interquartile et les valeurs aberrantes pour un diagramme en boîte.

Au moins 4 valeurs, séparées par des virgules ou des espaces

Résultat

Saisissez les valeurs et appuyez sur Calculer pour voir le résultat.

Formule

IQR=Q3−Q1\text{IQR} = Q_3 - Q_1

The spread of the middle half of the data.

x<Q1−1.5 IQR  or  x>Q3+1.5 IQRx < Q_1 - 1.5\,\text{IQR} \ \text{ or } \ x > Q_3 + 1.5\,\text{IQR}

A value outside these fences is an outlier.

Comment utiliser cette calculatrice

  1. Enter at least 4 numbers separated by commas, spaces or new lines.
  2. Press Calculate to get the five-number summary, the IQR and any outliers.

Exemple corrigé

Eight test scores

Sorted: 2, 4, 4, 5, 6, 7, 8, 30. The median is (5 + 6) ÷ 2 = 5.5.

Lower half 2, 4, 4, 5 gives Q1 = 4; upper half 6, 7, 8, 30 gives Q3 = 7.5.

IQR = 7.5 − 4 = 3.5. The fences are −1.25 and 12.75, so 30 is an outlier.

Questions fréquentes

Why does my spreadsheet give different quartiles?

There are several quartile methods. Sumzo uses the median-of-halves method taught in most schools; spreadsheet functions such as QUARTILE often interpolate instead.

Is the median included in the halves?

No. With an odd number of values the middle one is left out of both halves.

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