What symbol represents the sample mean?

The symbol that represents the sample mean is X̄ (pronounced "X bar"). In statistics, the sample mean is calculated by taking the sum of all values in a sample and dividing that by the total number of observations in the sample. This gives a single value that summarizes the central tendency of the data points collected.

X̄ is commonly used to indicate that this mean is derived from a sample, as opposed to μ, which denotes the population mean. When working with statistical data, it is important to differentiate between these two concepts, as they refer to different group sizes (sample vs. population). M represents the mean in some contexts, often related to different kinds of data analysis, but it is less frequently used than X̄ for indicating sample means. S typically denotes the standard deviation of a sample, which measures the amount of variation or dispersion of a set of values.

Recognizing these symbols is essential for understanding statistical notation and for accurately communicating findings and analyses in research contexts.