Population divides squared deviations by n; sample divides by n − 1.
Explore spread, variance and mean for a data set — population and sample standard deviation, the full deviation table that builds the answer, and quartiles with the interquartile range. Free and instant.
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Explore spread, variance and mean for a data set — population and sample standard deviation, the full deviation table that builds the answer, and quartiles with the interquartile range. Free and instant.
For 2, 4, 4, 4, 5, 5, 7, 9 the population mean is 5 and population standard deviation is 2. Sample standard deviation is about 2.1381. The deviation table shows each value minus the mean, squared — 9, 1, 1, 1, 0, 0, 4, 16 — summing to 32, and the quartiles are 4 and 5.5, an interquartile range of 1.5.
Population divides squared deviations by n; sample divides by n − 1.
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