I'm self teaching myself statistics and got stuck with notations; I'm working with multiple sources and notions seems to differ and confuse me a little, so I decided to write them down first.
$ \mu = $ mean of the population
$ \sigma = $ std deviation of the population
$ \bar X = $ mean of the sample
$ S = $ std deviation of the sample
$ \mu _ \bar X = \mu $ mean of the sample mean
$ \sigma_ \bar X = \sigma / \sqrt n $ std deviation of sample mean, aka mean standard error
It will be a silly question, but are all of these are correct? Are there any alternative notations for these?