Variance
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What is Variance?
The variance measures the spread between numbers in a dataset. Simply put, it measures how far each number in the set is from the mean (average). It helps us understand how spread out or consistent the values are in a dataset.
Variance is calculated by averaging the squared differences from the mean. First, find the mean of your data set. Then, subtract the mean from each data point, square those differences, sum them up, and finally, divide by either (n-1) for a sample or n for a population, where n is the number of data points.
Variance can't be interpreted in the original units of measurement due to its squared nature, which is why it is often used in conjunction with its square root, the standard deviation.
Free resources to learn Variance
- ArticleWhat is Variance?
- ArticleHow to Calculate Variance
More in stage 7: Variables and Data Types
Variance: common questions
Can I learn Variance in Hindi?
This lesson is written in English. Once you sign in, open it in the interactive course and ask the AI tutor to explain Variance in Hindi or Hinglish. The tutor answers from this lesson’s own text, so it stays on the syllabus, and it runs on your own Google, OpenAI or Anthropic key.
Is this Variance tutorial for beginners?
It is lesson 27 of 200 in the free BI Analyst roadmap, in stage 7, Variables and Data Types. If you are new to BI Analyst, start from stage 1 and come back here in order; if you already know the earlier stages, this lesson stands on its own.