Standard error

Standard error can refer to:Standard error (statistics) -- in statistics, an expression of the uncertainty in a value.One of the standard streams in Unix and Unix-like operating systems.
See more at Wikipedia.org...

In statistics, a measure of the possible error in an estimate. Plus or minus 2 standard errors usually provides a 95% confidence interval.

The standard error of the mean (first used by Yule, 1897) is the theoretical standard deviation of all sample means of size n drawn from a population and depends on both the population variance (sigma) and the sample size (n) as indicated below:
= ( 2/n)1/2
where
2 is the population variance and
n is the sample size.
Since the population variance is typically unknown, the best estimate for the standard error of the mean is then calculated as:
= (s2/n)1/2
where
s2 is the sample Variance (our best estimate of the population variance) and
n is the sample size.
See also, Descriptive Statistics Overview .

This is the standard deviation of the distribution of the sample proportion over repeated samples. If the population proportion is , and the sample size is N, the standard error of the proportion when sampling from an infinite population is
p= ( (1- )/N)**1/2
For more information see the chapter on Power Analysis .

Standard error
(Econ) Sai số chuẩn+ Một số đo mức độ mà một THỐNG KÊ được tính toán phân tán xung quanh TRUNG BÌNH của nó.
(C) 2007 www.TừĐiểnTiếngViệt.net