Standard Deviation
There’s a slight difference between standard deviation and pooled sample standard error:
- When we are talking about a population, we talk about standard deviations.
- When we talk about a sample we call it a standard error.
Population Standard Deviation
Sample Standard Deviation
-
| | | | :--- | :--- | | Standard deviation | a measure of how much your data is spread out | | Error propagation 錯誤傳播 | 變量含有誤差，而使函數受其影響也含有誤差，稱之為誤差傳播 | | RSD - Relative standard deviation | Relative standard deviation= 100 * s / |x̄|, whether the “regular” std dev is a small or large quantity when compared to the mean for the data set | | Absolute deviation | Absolute deviation = |x – x̄|, the distance between each value in the data set and that data set’s mean or median |
Relative standard deviation= 100 * s / |x̄|
- Absolute deviation = |x – x̄|
- average deviation formula: Dx = (|x1 – x̄| + |x2 – x̄| +…+ |x3 – x̄|) / N