Variance Formula

What is Variance?

We measure the various values of the data and these values are used for a variety of purposes. The data can be given in two types grouped data, or ungrouped (discrete) data. If the data is given in the form of class intervals it is called grouped data whereas if the data is given in the form of a single data point it is referred to as a discrete or ungrouped data point. Variance is the measure of the dispersion of the data concerning the mean value of the data. It tells us how the data is dispersed in the given data value. We can easily calculate the sample variance and population variance for both grouped and ungrouped data....

Types of Variance

We can define the variance of the given data in two types,...

Variance Symbol

The symbol for variance is typically represented by the Greek letter sigma squared (σ²) when referring to the population variance. For sample variance, it’s often denoted by s²....

Variance Example

We can understand the concept of variance with the help of the example discussed below....

Variance Formula

The variance for a data set is denoted by the symbol σ2. For population data, its formula is equal to the sum of squared differences of data entries from the mean divided by the number of entries. While for sample data, we divide the numerator value by the difference between the number of entries and unity....

How to Calculate Variance?

In general, variance means population standard variance. The steps to calculate the variance of a given set of values is,...

Variance and Standard Deviation

Variance and Standard Deviation both are measures of the central tendency that is used to tell us about the extent to which the values of the data set deviate with respect to the central or the mean value of the data set....

Variance and Covariance

Variance of the data set defines the volatility of all the values of the data set with respect to the mean value of the data set. Covariance tells us how the random variables are related to each other and it tells us how the change in one variable affects the change in other variables....

Variance Properties

Variance is widely used in Mathematics, Statistics, and other branches of science for a variety of purposes. Variance has various properties which are widely used for solving various problems. Some of the basic properties of the variance are,...

Examples on Variance Formula

Example 1: Calculate the variance of the sample data: 7, 11, 15, 19, 24....

Summary – Variance

Variance is a statistical measure that shows how much the values in a data set differ from the mean. It helps us understand the spread or dispersion of data points. There are two main types of variance: population variance, which measures how data points in a whole population spread out, and sample variance, which measures how data points in a sample spread out. Variance is denoted by σ² and is the square of the standard deviation. To calculate variance, you find the mean of the data, subtract the mean from each data point, square the differences, and then average these squared differences. Variance is important because it helps us understand the variability within a dataset. A high variance indicates that data points are spread out widely, while a low variance indicates they are close to the mean. Variance is always non-negative since it involves squaring the differences....

FAQs on Variance

What is Variance in Statistics?...