Standard Error of the Sample Mean

Thursday, 15 August 2019

11:57 PM

Machine generated alternative text: 7. Inferences concerning a mean 7.2 Point estimation Standard error of the sample mean Suppose again that we estimate the mean of a population with the sample mean X calculated from a random sample of size n. 2 We know that E(X) = and Var(X) so the standard error of X as an estimator of is sd(X) - However, we cannot report a numerical value for this standard error as it depends in turn on the population standard deviation a, which is usually unknown. + we have a natural estimate of the population standard deviation given by the observed sample standard deviation s 1 n—l + estimate the standard error sd(X) with sd(X) s Note: we will study the sample standard deviation S as an estimator of in more detail later (Cha ter 9) MATH2099/2859 (Statistics) Dr Jia Deng Term 2, 2019 - Lecture 5 24/ 56

 

 

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