The Mean, Standard Deviation, and Sampling Distribution of the Sample Mean

The Mean and Standard Deviation of the Sample Mean

Key Takeaways

The sample mean is a random variable; as such it is written $\bar{X}$ , and $\bar{x}$ stands for individual values it takes.
As a random variable the sample mean has a probability distribution, a mean $\mu_{\bar{X}}$ , and a standard deviation $\sigma_{\bar{X}}$ .
There are formulas that relate the mean and standard deviation of the sample mean to the mean and standard deviation of the population from which the sample is drawn.

Callback before_footer in local_aigrade component should be migrated to new hook callback for core\hook\output\before_footer_html_generation

line 7225 of /lib/moodlelib.php: call to debugging()
line 7292 of /lib/moodlelib.php: call to {closure}()
line 71 of /lib/classes/hook/output/before_footer_html_generation.php: call to get_plugins_with_function()
line 987 of /lib/classes/output/core_renderer.php: call to core\hook\output\before_footer_html_generation->process_legacy_callbacks()
line 97 of /mod/book/tool/print/index.php: call to core\output\core_renderer->footer()