The following are the two main reasons.
It is the estimate for s, the sample standard deviation.
Deviation, actually called "standard deviation" is, in a set of numbers, the average distance a number in that set is away from the mean, or average, number.
No. Not at all. Whoever told you that fails statistics forever.
Are you talking of this in means of Statistics? If you are, then the variation from the mean is measured in standard deviation.
Coefficient of deviation (CV) is a term used in statistics. It is defined as the ratio of the standard deviation (sigma) to the mean (mu). The formula for CV is CV=sigma/mu.
Parametric and non-parametric statistics.Another division is descriptive and inferential statistics.Descriptive and Inferential statistics. Descriptive statistics describes a population (e.g. mean, median, variance, standard deviation, percentages). Inferential infers some information about a population (e.g. hypothesis testing, confidence intervals, ANOVA).
Standard deviation in statistics refers to how much deviation there is from the average or mean value. Sample deviation refers to the data that was collected from a smaller pool than the population.
Sas, spss
It is the estimate for s, the sample standard deviation.
Deviation, actually called "standard deviation" is, in a set of numbers, the average distance a number in that set is away from the mean, or average, number.
No. Not at all. Whoever told you that fails statistics forever.
Are you talking of this in means of Statistics? If you are, then the variation from the mean is measured in standard deviation.
Coefficient of deviation (CV) is a term used in statistics. It is defined as the ratio of the standard deviation (sigma) to the mean (mu). The formula for CV is CV=sigma/mu.
Since this is regarding statistics I assume you mean lower case sigma (σ) which, in statistics, is the symbol used for standard deviation, and σ2 is known as the variance.
A standard deviation calculator allows the user to find the mean spread away from the mean in a statistical environment. Most users needing to find the standard deviation are in the statistics field. Usually, the data set will be given and must be typed into the calculator. The standard deviation calculator will then give the standard deviation of the data. In order to find the variance of the data, simply square the answer.
Information is not sufficient to find mean deviation and standard deviation.
Inferential statistics is the practice of sampling large sets of data (usually at random) to gain information about the population as a whole. Sampling is used because measuring everything in the population can consume too many resources (time, money, etc.) I suggest looking at these topics for an intro into inferential statistics: 1) Sampling (random, stratified, etc) 2) Mean, variance/standard deviation, median, and mode 3) Data distributions 4) Confidence intervals 5) T-tests 6) Analysis of variance 7) Trend analysis (regression) 8) Association analysis ... and many more!