Standard deviation is a statistic measuring the dispersion of a dataset relative to its mean. It is calculated as the square root of the variance. Learn how it's used.

The standard deviation formula for a sample is almost the same as the formula for a population, except you subtract N by 1 in the denominator, so it's: σ = √(Σ(xi - μ)² / N-1).

Another way to interpret the normal distribution is to say that the probability of Apple’s return (at a range of -1.83 percent and 1.99 percent) falling within -1 and 1 standard deviation from ...

Standard deviations are important here because the shape of a normal curve is determined by its mean and standard deviation. The mean tells you where the middle, highest part of the curve should go.

The formula for pooled standard deviation. In the formula above, n is the sample size of the group, S squared the group ...

Standard deviation is a measure of how far away individual measurements tend to be from the mean value of a data set. The standard deviation of company A's employees is 1, while the standard ...

Standard deviation measures how far numbers in a data set are spread out from an average value. In investing, it is used as a measurement of portfolio volatility.

For example, if your mean is in cell A2, population mean in cell B2, standard deviation in cell C2, square root of degrees of freedom in E2, type the formula as =(A2-B2)/(C2/E2) to generate the T ...

The formula for annualized volatility is the standard deviation of the data multiplied by the square root of the number of time periods in the year the data is collected (i.e., 12 for a monthly ...

Were that to occur, the standard-deviation calculation would be unfair, because it would penalize fund managers for excelling at their jobs. If a fund gains 7% when the stock market rises by 5% ...