Population mean意思

"Population mean" is a statistical term that refers to the average value of a variable for an entire population. In statistics, a population is the entire group of individuals or items of interest, while a sample is a subset of that population. The mean (average) is a measure of central tendency, which is a way to describe the center or typical value of a distribution of data.

When talking about the population mean, we are referring to the theoretical average value of a variable for all members of the population. This value is often denoted by the Greek letter μ (mu). To calculate the population mean, you would add up all the values of the variable for every member of the population and then divide by the total number of members in the population.

In practice, it is often not feasible or possible to measure every member of a population, so statisticians typically use samples to estimate population parameters. The mean of a sample is called the sample mean and is denoted by the Greek letter Σ (sigma). The sample mean is used to estimate the population mean. The larger and more representative the sample, the more accurate the estimate of the population mean will be.