Standard deviation of sample variance

Calculates the standard deviation of the variance estimate

sd.var(x)

Arguments

x	sample

Value

estimate of standard deviation of the sample variance

Details

Uses the equation ^4(2n-1+n)

References

Mood, Graybill, Boes 1974 'Introduction to the Theory of Statistics' 3rd ed. p 229; Casella and Berger 'Statistical Inference' p 364 ex. 7.45; 'Reference for Var(s^2)' CrossValidated http://stats.stackexchange.com/q/29905/1381, 'Calculating required sample size, precision of variance estimate' CrossValidated http://stats.stackexchange.com/q/7004/1381, 'Variance of Sample Variance?' Mathematics - Stack Exchange http://math.stackexchange.com/q/72975/3733