Mean and variance are common calculations for statistics.
Variance is a common formula used in statistics. Variance looks at how much a number is different from the mean of all the numbers. In order to calculate the variance between two numbers, you need to know the mean of the two numbers. Mean is also known as average. Once you compute variance, you can take the square root of the number in order to find the standard deviation between the two numbers as well.
Instructions
1. Find the mean of the two numbers by adding the numbers together and dividing by 2. For example, assume your numbers are 25 and 11. So, 25 plus 11 equals 36, and 36 divided by two equals 18. This is the mean.
2. Subtract the mean from both numbers. This is the difference from the mean. In the example, 25 minus 18 equals 7 and 11 minus 18 equals -7.
3. Square both differences from the mean. In the example, 7 squared and -7 squared equals 49 for both numbers.
4. Add together the squares of the differences from the mean. In the example, 49 plus 49 equals 98. Divide the result by 2 to find the variance. So, the variance equals 49.
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