How to correctly pronounce variance and what is its meaning for better understanding
variance
noun
How to pronounce variance?
The word variance sounds like var-i-ance
/'vɜriəns/
What is the definition of variance?
nouna difference between conflicting facts or claims or opinions
nounan activity that varies from a norm or standard
noundiscord that splits a group
nounan event that departs from expectations
nounthe quality of being subject to variation
nounan official dispensation to act contrary to a rule or regulation (typically a building regulation)
Examples
- a zoning variance
nounthe second moment around the mean; the expected value of the square of the deviations of a random variable from its mean value
What does the word 'variance' mean?
- Variance is a statistical measure that describes the spread or dispersion of a set of data points around their mean (average).
- It is calculated as the average of the squared differences from the Mean.
How is variance used in statistics?
- Variance is used to quantify the degree of spread in a data set.
- It helps in understanding the variability of data, comparing distributions, and in fields like finance and science to assess risk and consistency.
What is the formula for variance?
- For a population, variance (σ²) = sum of squared deviations from the mean divided by the number of data points (N).
- For a sample, variance (s²) = sum of squared deviations from the mean divided by (n-1), where n is the sample size.
What is the difference between variance and standard deviation?
- Standard deviation is the square root of variance.
- While variance measures variability in squared units, standard deviation provides a measure in the original units, making it more interpretable.
Can variance be negative?
- No, variance cannot be negative because it is calculated as an average of squared differences, which are always non-negative.
What are some common uses of variance?
- Variance is used in fields like finance to assess investment risk, in quality control to measure process variability, and in medicine to analyze variability in biological measurements.
How does variance relate to data distribution?
- Variance influences the shape of the data distribution; higher variance indicates data is more spread out, while lower variance signifies data is more tightly clustered around the mean.
What is the population vs. sample variance?
- Population variance (σ²) considers all members of a population.
- Sample variance (s²) estimates the population variance based on a subset (sample) and uses (n-1) in the denominator to correct bias.
What are units of variance?
- Units of variance are the square of the units of the data. For example, if data is in meters, the variance is in square meters.
How do you interpret variance?
- A small variance indicates data points tend to be close to the mean.
- A large variance indicates data points are more spread out, which may suggest variability or inconsistency in the dataset.
