Appendix B - Commonly used statistical formulas
For better quality, print this page.
Mean (Average)
Variance (when you have measured all members of a population)
![]()
Sample variance (when you are estimating variance from a sample of population)
![]()
Standard deviation (when all members of a population are measured)
![]()
Sample standard deviation
![]()
Standard error (of the mean)
![]()
Chi-square value
c
2 ![]()