Calculadora de Variância

The Variance Calculator computes the sample variance of up to 7 numerical values. Sample variance measures the dispersion of data around the mean, being essential for understanding variability in a sample. The calculation follows the formula s² = Σ(xᵢ − x̄)² / (n − 1), where x̄ is the sample mean and n is the number of observations. The result indicates, on average, how much each value deviates from the mean squared.

To use the calculator, enter values separated by commas, spaces, or line breaks in the input field. The tool accepts integers or decimals. After clicking 'Calculate', it displays the mean, sum of squared differences, and sample variance. Note that variance is expressed in the squared unit of the original data, which may hinder direct interpretation; standard deviation (square root of variance) is often used instead.

This calculator is useful in basic statistics, quality control, experimental data analysis, and academic research. For example, when comparing the dispersion of student grades in two classes, sample variance helps identify which class has more homogeneous results. However, remember that the formula with denominator n−1 is specific to samples; for entire populations, use population variance (with n in the denominator).

Cautions: the calculator does not verify if values are plausible or represent a random sample. Also, variance is sensitive to outliers, which can inflate the result. For datasets with fewer than 2 values, calculation is impossible because denominator n−1 would be zero. Always interpret variance in context and consider using other dispersion measures, such as interquartile range, if outliers are present.