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You can also use this Variance Calculator as a Sample Variance Calculator by following steps:
According to probability theory and statistics, a variance is the probability of the squared deviation of a random variable from its mean. Casually, it measures how far a set of (random) numbers are spread out from their average value. Variance has a vital role in statistics, where some ideas that use it include expressive statistics, statistical supposition, hypothesis testing, goodness of fit, and Monte Carlo sampling. A variance is a vital tool in the sciences, where statistical analysis of data is ordinary.
Sample question: Find the population variance of the age of children in a family of five children aged 16, 11, 9, 8, and 1:
Step 1: Find the mean, μx:
μ = 9.
Step 2: Subtract each data point from the mean, then square the result:
(16-9)2 = 49
(11-9)2 = 4
(9-9)2 = 0
(8-9)2 = 1
(1-9)2 = 64.
Step 3: Add up all of the squared differences from Step 2:
(16-9)2 + (11-9)2 + (9-9)2 + (8-9)2+ (1-9)2 = 118.
Step 4: Divide Step 3 by the number of items. 118/5 gives a population variance of 23.6.