Definition of variance in statistics
What is variance in statistics definition?
The variance is a measure of variability. It is calculated by taking the average of squared deviations from the mean. Variance tells you the degree of spread in your data set. The more spread the data, the larger the variance is in relation to the mean.
Which is the best definition for variance?
The term variance refers to a statistical measurement of the spread between numbers in a data set. More specifically, variance measures how far each number in the set is from the mean (average), and thus from every other number in the set.
What is variance in simple terms?
Variance is a measure of how data points differ from the mean. According to Layman, a variance is a measure of how far a set of data (numbers) are spread out from their mean (average) value. Variance means to find the expected difference of deviation from actual value.
What is the full meaning of variance?
Definition of variance
1 : the fact, quality, or state of being variable or variant : difference, variation yearly variance in crops. 2 : the fact or state of being in disagreement : dissension, dispute. 3 : a disagreement between two parts of the same legal proceeding that must be consonant.
What is variance with example?
Examples Using Variance Formula
| xi | (xi – xÌ„) | (xi – xÌ„)2 |
|---|---|---|
| 34 | -16 | 256 |
| 77 | 27 | 729 |
| 54 | 4 | 16 |
| μx = Σxi10=50010 Σ x i 10 = 500 10 = 50 units | σx = Σ(xi−¯x)210=408410 Σ ( x i − x ¯ ) 2 10 = 4084 10 = 408.4 units2 |
What is another word for variance in statistics?
Also called mean square deviation.
What is another name of variance?
Some common synonyms of variance are conflict, contention, discord, dissension, and strife. While all these words mean “a state or condition marked by a lack of agreement or harmony,” variance implies a clash between persons or things owing to a difference in nature, opinion, or interest.
What is variance vs standard deviation in statistics?
Variance is the average squared deviations from the mean, while standard deviation is the square root of this number. Both measures reflect variability in a distribution, but their units differ: Standard deviation is expressed in the same units as the original values (e.g., minutes or meters).
Why do we use variance?
The term variance is a statistical concept related to the spread or dispersion of a set of data. Second to the mean, it a common value we may calculate. We find standard deviation easier to understand and use (it uses the same units as the data) whereas variance uses the units squared.
What is the unit of variance?
Variance: The variance (denoted σ2) represents the spread (the dispersion) of the repeated measurements either side of the mean. As the notation implies, the units of the variance are the square of the units of the mean value.
What is the formula for calculating variance?
For a population, the variance is calculated as σ² = ( Σ (x-μ)² ) / N. Another equivalent formula is σ² = ( (Σ x²) / N ) – μ². If we need to calculate variance by hand, this alternate formula is easier to work with.
How is sample variance calculated?
Add all data values and divide by the sample size n. Find the squared difference from the mean for each data value. Subtract the mean from each data value and square the result. Find the sum of all the squared differences.
What is range of variance?
Range: the difference between the highest and lowest values. Interquartile range: the range of the middle half of a distribution. Standard deviation: average distance from the mean. Variance: average of squared distances from the mean.
What is the value of the variance?
The variance (σ2), is defined as the sum of the squared distances of each term in the distribution from the mean (μ), divided by the number of terms in the distribution (N).
What is a high variance value?
A high variance tells us that the collected data has higher variability, and the data is generally further from the mean. A low variance tells us the opposite, that the collected data is generally similar, and does not deviate much from the mean.
Is variance can be zero?
Answer and Explanation: Zero variance means that there is no difference in the data values, which means that they are all the same. The mean of the above data is 8, and hence, by substituting in the sample variance formula, it results in a zero.
What does a variance of 1 mean?
Very large variance means relative large number of values are far from the expectation. There is nothing special about variance of 1.
Can you have negative variance?
Can variance be negative? The answer: No, variance cannot be negative. The lowest value it can take on is zero. To find out why this is the case, we need to understand how variance is actually calculated.