Descriptive Statistics
Descriptive statistics are summary statistics that quantitatively describe or summarize features from a collection of information. This calculator provides a complete overview of the central tendency, dispersion, and shape of a dataset's distribution.
Sample vs. Population
When dealing with standard deviation and variance, it's crucial to know whether your data represents an entire Population or just a Sample. A population includes all members of a defined group, while a sample is a subset. Sample variance applies Bessel's correction (dividing by N-1 instead of N) to correct bias in the estimation of a population variance.
Central Tendencies
- Mean (Average)Sum of values ÷ Count
- MedianThe middle value (when sorted)
- ModeThe most frequent value
Geometric Mean
The geometric mean is a type of average that uses the product of the values in a set to indicate central tendency. It is especially useful in cases where the values being compared vary largely or represent proportional growth (e.g., compound interest, aspect ratios).
Note that the geometric mean can only be calculated for datasets containing strictly positive numbers.
Measures of Spread
Central tendency alone doesn't tell the whole story. Two datasets can have the exact same mean but entirely different distributions. Measures of spread like Range, Variance, and Standard Deviation describe how "spread out" the numbers are.