What symbol is commonly used to denote the sample variance?

What symbol is commonly used to denote the sample variance?

• A. s^2
• B. σ^2
• C. r^2
• D. μ^2

Answer: (A)

When we talk about how spread out the data in a sample are, we use the sample variance, denoted by s^2. The lowercase s signals a quantity computed from a sample, and squaring it gives the variance of that sample. The population variance, the true variability in the entire population, is written as σ^2. The symbol r represents the correlation coefficient, and r^2 is its square, which tells us the proportion of variance explained in a regression, not the variance itself. μ stands for the population mean, and μ^2 would be the square of the mean rather than a measure of spread. So s^2 is the standard notation for the sample variance.

When we talk about how spread out the data in a sample are, we use the sample variance, denoted by s^2. The lowercase s signals a quantity computed from a sample, and squaring it gives the variance of that sample. The population variance, the true variability in the entire population, is written as σ^2. The symbol r represents the correlation coefficient, and r^2 is its square, which tells us the proportion of variance explained in a regression, not the variance itself. μ stands for the population mean, and μ^2 would be the square of the mean rather than a measure of spread. So s^2 is the standard notation for the sample variance.