Population vs sample SD?

Population divides by n; sample divides by n-1 (Bessel's correction).

Mean is better for symmetric data; median is better for skewed data or when outliers exist.

IQR measures spread of the middle 50%. Outliers: values below Q1-1.5×IQR or above Q3+1.5×IQR.

Descriptive Statistics Calculator

Calculate mean, median, mode, standard deviation, variance, quartiles, IQR from any dataset. Includes a visual box plot.

Complete User Guide

Enter data values separated by commas or spaces. Get mean, median, mode, std dev, variance, quartiles Q1/Q2/Q3, IQR, min, max, and a visual box plot.

The Mathematical Formula

σ = √[Σ(xi - μ)² / n]

Mean μ = Σxi/n. Variance σ² = Σ(xi-μ)²/n. Std dev σ = √σ². Median = middle value when sorted. IQR = Q3-Q1.

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