Variance formula: In probability theory and

In probability theory and statistics, the variance formula measures how far a set of numbers are spread out. It is a numerical value and is used to indicate how widely individuals in a group vary. If individual observations vary considerably from the group mean, the variance is big and vice versa. A variance of zero indicates that all the values are identical. It should be noted that variance is always non-negative- a small variance indicates that the data points tend to be very close to the ... Variance and standard deviation measure how much data deviates from the mean. Variance gives the average squared deviation, while standard deviation (the square root of variance ) expresses the spread in the same unit as the data. Variance is a measure of dispersion that is used to check the spread of numbers in a given set of observations with respect to the mean. Understand variance using solved examples. 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 is often denoted by s². Formula for Calculating Variance The formula used for calculating the Variance is discussed in the image below: We will explain both formulas in detail below, covering the population and sample cases.