and keep it clean,its for my son's homework!!
2006-10-12 11:26:46 · 5 answers · asked by Anonymous in Education & Reference ➔ Homework Help
http://en.wikipedia.org/wiki/Standard_deviation, check this out.
2006-10-12 11:35:58 · answer #1 · answered by hakuna matata 4 · 0⤊ 0⤋
The standard deviation is a statistic that tells you how tightly all the various examples are clustered around the mean 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.
2006-10-12 18:34:46 · answer #2 · answered by Violet Pearl 7 · 0⤊ 0⤋
Find the average of all samples. That is the mean. Subtract the mean from every sample and square all of those differences. Add up all of those squares. Divide the total by one less than the number of samples. Now take that quotient and find the square root. That square root is the standard deviation. It's a measure of how far most of the samples are from the mean. About 63% of samples will fall within 1 standard deviation from the mean.
2006-10-12 18:55:08 · answer #3 · answered by robertspraguejr 4 · 0⤊ 0⤋
Just a word of warning. Pablovp is confusing Mean Deviation with Standard Deviation. They are not the same.
Just follow the links provided by other contributors to the wikipedia article.
2006-10-12 19:33:16 · answer #4 · answered by Hal W 3 · 0⤊ 0⤋
put simply, it is the mean deviation from the mean. the higher the number, the more spread out the data is, and consequently the less reliable the mean is.
2006-10-12 19:03:20 · answer #5 · answered by pablovp 1 · 0⤊ 0⤋