STANDARD DEVIATION
A calculation that essentially describes the error for a single point of a sample. It can only be rigorously calculated when more than one data point has been measured. The calculation is :
where
:
is the
data observations
is the mean of the data
n is the number of observations
When only a few points have been measured and it is necessary to know the confidence that one can assign to the precision, the use of the Student's "t" factor is often applied.