ref: 374e6e87b1b13492438a2c030edd191cbebe94dc
dir: sm2/stt/stddeviation.t
The standard deviation of a variable X is computed as...
.Bp
The standard deviation of a variable X is computed as:
.EQ
s = sqrt {{sum from 0 to N ({X sub i} - {X highbar}) sup 2} over {N - 1}}
.EN