Calculate all four measures of central tendency and spread with complete step-by-step working. Ideal for students, teachers, and Australian curriculum revision.
Enter numbers separated by commas or spaces. Works with decimals and negative numbers.
| Statistic | Value | Statistic | Value |
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These four measures are a core part of the Australian Curriculum: Mathematics (Statistics and Probability strand) taught from Year 5 through Year 10.
The mean is the sum of all values divided by the count. Formula: x̄ = (Σxᵢ) / n. It is sensitive to extreme values (outliers).
The median is the middle value when data is sorted. For an even number of values, average the two middle values. The median is robust — not affected by extreme outliers.
The mode is the value that appears most often. A dataset can have no mode (all values unique), one mode (unimodal), or multiple modes (bimodal, multimodal).
Range = Maximum − Minimum. It gives a simple measure of spread but is very sensitive to outliers. Better measures of spread include IQR and standard deviation.
| Situation | Best measure |
|---|---|
| Symmetric data, no outliers | Mean |
| Skewed data or outliers present | Median |
| Categorical data or "most popular" | Mode |
| Quick spread estimate | Range |