a quantity formerly used as a measure of variability: equal to 0.6745 times the standard deviation. A normally distributed population has half of its elements within one probable error of the mean.
Origin of probable error
First recorded in 1805–15
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
The amount by which the arithmetic mean of a sample is expected to vary because of chance alone.
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