What is standard Deviation, what does it show?
The standard deviation is a statistic that tells you how tightly all the various examples are clustered around the mean (middle or average) in a set of data. When the examples are pretty tightly bunched together and the bell-shaped curve is steep, the standard deviation is small. When the examples are spread apart and the bell curve is relatively flat, that tells you you have a relatively large standard deviation. One standard deviation away from the mean in either direction accounts for somewhere around 68 percent of data. Two standard deviations away from the mean accounts for roughly 95 percent of data. And three standard deviations accounts for about 99 percent of the data. Answer originally posted in response to Could you please explain standard deviation?
