# 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 , and stands for individual values it takes.
- As a random variable the sample mean has a probability distribution, a mean , and a standard deviation .
- 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.