Math Teacher Question:

Answer #1
Standard deviation is the measure of the spreadout of the data about the mean value. It is referred as sigma and represented as symbol σ.

Answer #2
One standard deviation is represented by a specific range from the mean value of the variables of one sample. It us usually a 'slice' of a bell curve, for instance. With the distance from the mean and the curve itself you can calculate the area UNDER the curve which will represent the distance or difference from the mean in which a certain percent of the sample set should be.In short, more things will be fairly close to average, whereas only a small percetage will be far far below average or far far above average.. Its a way of measureing what percent will fall close and what percent will fall far.