Calculate the variance of a data set with this calculator!
Answer
Learn about Variance
Variance is a the statistical measure of how densely located a data set is relative to the mean. A large variance reflects a data set with a large range relative to the mean, while a small variance indicates that most of the data is clustered around the mean. Variance often goes hand in hand with Normal Distribution, also known as the Bell Curve, which has the mean evenly surrounded by all other data points.
The equation for finding variance can be intimidating, but becomes easy once it gets broken down into smaller steps. Take the following data set.To calculate variance first requires knowing the mean, or mathematical average, of the data set, represented by $\mu$. The mean of this data set is 18. For help finding the mean, check out mean calculator. To find the variance of a data set, the deviations of each individual data point must be found. To find the deviation, subtract the mean from each data point and then square the resulting number.Sum the resulting deviations together. For help summing large sets of numbers, check out our addition tool. The final piece of information needed is the total number of objects in the set, marked by the $N$ in the equation. In this equation there are 6 data points. For help counting larger sets of data, check out counting tool. With all the information assembled, the last step is to evaluate the equation.If finding the mean for a sample set of data, rather than the complete population of data points, use N-1 instead of N for the final calculation.
The mean of the data set is 24.92, and there are 12 data points in the set.Calculate the sum of each individual deviation by subtracting the mean from each data point and squaring the difference, then adding together all the results.With both numbers in hand, the variance can be calculated. To find the variance if the data represents a sample set, remember to subtract one from the number of data points in the set, which would be 11.The mean of the data set is 1.43, and there are 7 data points in the set.Calculate the sum of each individual deviation by subtracting the mean from each data point and squaring the difference, then adding together all the results.With both numbers in hand, the variance can be calculated. To find the variance if the data represents a sample set, remember to subtract one from the number of data points in the set, which would be 6.The mean of the data set is 68.12, and there are 17 data points in the set.Calculate the sum of each individual deviation by subtracting the mean from each data point and squaring the difference, then adding together all the results.With both numbers in hand, the variance can be calculated. To find the variance if the data represents a sample set, remember to subtract one from the number of data points in the set, which would be 16.
Watch detailed video tutorials about Variance!
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