When does the standard error of the mean decrease?

1 Answer
Dec 3, 2017

To decrease standard error, we need to draw larger sample size.

Explanation:


Standard deviation of Sample mean or Standard error:

#SE = \sigma_{ \bar{x}} = \frac{\sigma}{\sqrt{n}} #

As we see, the standard error decreases if either population standard deviation is small (#\sigma#), or sample size is large (#n#). In general, we have no control over #\sigma#, so to decrease standard error, we need to increase the sample size (#n#)