How to calculate variance and standard deviation
How to calculate variance and standard deviation? [1]
Definition:
To illustrate the variability of a group of scores, in statistics, we use "variance" or "standard deviation". We define the deviation of a single score as its distance from the mean: Variance is symbolized by ( 2. Standard Deviation is (. N is the number of scores.
However, when the data of a sample are used to estimate the variance of the population from which the sample was drawn, the population variance estimate is computed instead:
Summary of the calculation procedures:
1. subtract the mean from each score
2. square each result
3. sum all the square
4. divide the sum of square by N. Now you get variance
If divide the sum of square by N-1, you will get the population variance estimate
5. Standard deviation is just the positive square root of the variance
-----------------------
[1] Cited by Yue Yin from Welkowitz, J, Ewen, R & Cohen, J page 56-58.
-----------------------
[pic]
[pic]
[pic]
[pic]
[pic]
................
................
In order to avoid copyright disputes, this page is only a partial summary.
To fulfill the demand for quickly locating and searching documents.
It is intelligent file search solution for home and business.
Related download
- average standard deviation and relative standard deviation
- variance and standard deviation
- calculating mean and standard deviation for a sample with
- calculating the mean and standard deviation on a calculator
- calculating mean and standard deviation ti 89
- sd for difference between means
- annex calculation of mean and standard deviation
- mean median box whisker plots
- standard deviation
- casio calculator fx 83es