Symbols and naming in confidence interval
Suppose to have a confidence interval for the mean on a large sample, i.e.
$$\overline{X}-z_{\frac{\alpha}{2}}\frac{\sigma}{\sqrt{n}} \le \mu \le \overline{X}+z_{\frac{\alpha}{2}}\frac{\sigma}{\sqrt{n}}$$
Exists any common used symbol to address the $z_{\frac{\alpha}{2}}\cdot\frac{\sigma}{\sqrt{n}}$ term? Any reference is appreciated.
$\endgroup$ 22 Answers
$\begingroup$I found here that $z_{\frac{\alpha}{2}}\cdot\frac{\sigma}{\sqrt{n}}$ is named "margin of error m".
I hope it is a widely used notation.
$\endgroup$ $\begingroup$For what it's worth: The term $\frac{\sigma}{\sqrt{n}}$ is called the standard error of the estimator $\bar{X}$, and is often denoted by $\mathrm{SE}(\bar{X})$. Hence your confidence interval can be written $$ \bar{X}-z_{\alpha/2}\mathrm{SE}(\bar{X})\leq \mu\leq \bar{X}+z_{\alpha/2}\mathrm{SE}(\bar{X}). $$
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