Hi, I have a question and I hope anyone could answer it:
The standard deviation of a series of observations
A. Is related to the scatter of the observations.
B. Is such that about 95 per cent of observations lie within one standard deviation of the mean.
C. Should be calculated only if observations are normally distributed.
D. Is a measure of the significance of the observations.
E. Is a more valid expression of scatter than is the absolute range for small numbers of observations, e.g. less than five.