Standard deviation is the square root of the mean. The mean for this set is (2 + 4 + 3 + 7)/4 = 16/4 = 4; the square root of this is 2.
Standard deviation is the square root of the variance. Since you stated the variance is 4, the standard deviation is 2.
From the online calculator, see related link, the standard deviation is 4.06202.
http://www.hedgefund.net/pertraconline/statbody.cfmStandard Deviation -Standard Deviation measures the dispersal or uncertainty in a random variable (in this case, investment returns). It measures the degree of variation of returns around the mean (average) return. The higher the volatility of the investment returns, the higher the standard deviation will be. For this reason, standard deviation is often used as a measure of investment risk. Where R I = Return for period I Where M R = Mean of return set R Where N = Number of Periods N M R = ( S R I ) ¸ N I=1 N Standard Deviation = ( S ( R I - M R ) 2 ¸ (N - 1) ) ½ I = 1Annualized Standard DeviationAnnualized Standard Deviation = Monthly Standard Deviation ´ ( 12 ) ½ Annualized Standard Deviation *= Quarterly Standard Deviation ´ ( 4 ) ½ * Quarterly Data
The formula for standard deviation has both a square (which is a power of 2) and a square-root (a power of 1/2). Both must be there to balance each other, to keep the standard deviation value's magnitude similar to (having the same units as) the sample numbers from which it's calculated. If either is removed from the formula, the resulting standard deviation value will have different units, reducing its usefulness as a meaningful statistic.
The standard deviation of 2 3 5 6 = 1.8257
The answer depends on the degrees of freedom (df). If the df > 1 then the mean is 0, and the standard deviation, for df > 2, is sqrt[df/(df - 2)].
68% of the scores are within 1 standard deviation of the mean -80, 120 95% of the scores are within 2 standard deviations of the mean -60, 140 99.7% of the scores are within 3 standard deviations of the mean -40, 180
The standard deviation of 2 3 5 6 = 1.8257
2 times the standard deviation!
4.55% falls outside the mean at 2 standard deviation
standard diviation is variance1/2
Standard deviation is the square root of the variance. Since you stated the variance is 4, the standard deviation is 2.
Variance = 17.9047619 Standard Deviation = 4.23140188
Standard deviation is basically how much your scores vary from the mean or average score. So if you have a mean of 5 and a standard deviation of 2 it indicates that most of your values are around 5, and if they are not they will usually be +/- 2 units different (between 3 and 7). If you have a large standard deviation it simply means that your data includes a wide range of values. In some cases it may mean that you have an outlier, or an error in your data, in other cases it is normal depending on what you are measuring.For example if you are taking a sample of peoples ages and you get a mean of 50 and a standard deviation of 20 that would be normal because you can expect ages to range from 0-100. But if you are measuring shoe size and you get a mean of 8 and a standard deviation of 6 you can expect that something is wrong with your data because not many people have size 2 or size 14 shoes.
From the online calculator, see related link, the standard deviation is 4.06202.
standard deviation is the square roots of variance, a measure of spread or variability of data . it is given by (variance)^1/2
1. Standard deviation is not a measure of variance: it is the square root of the variance.2. The answer depends on better than WHAT!