Standard Error Calculator — 公式
## How to Calculate the Standard Error
### Formula
**SE = sigma / sqrt(n)**
The standard error of the mean measures the precision of the sample mean as an estimator of the population mean. It is the standard deviation of the sampling distribution of the mean. As sample size increases, SE decreases, making estimates more precise.
### Formula
**SE = sigma / sqrt(n)**
The standard error of the mean measures the precision of the sample mean as an estimator of the population mean. It is the standard deviation of the sampling distribution of the mean. As sample size increases, SE decreases, making estimates more precise.
计算示例
Population SD = 15, sample size = 25. What is the standard error?
- SE = sigma / sqrt(n)
- SE = 15 / sqrt(25)
- SE = 15 / 5 = 3
- Variance of mean = 15^2 / 25 = 225 / 25 = 9