ref: 00b235d6d62eb18a0327561fea4ba9eae23cdcf7
dir: /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