standard deviation of errors
71Correlation and dependence — This article is about correlation and dependence in statistical data. For other uses, see correlation (disambiguation). In statistics, dependence refers to any statistical relationship between two random variables or two sets of data. Correlation …
72Central limit theorem — This figure demonstrates the central limit theorem. The sample means are generated using a random number generator, which draws numbers between 1 and 100 from a uniform probability distribution. It illustrates that increasing sample sizes result… …
73Item response theory — In psychometrics, item response theory (IRT) is a body of theory describing the application of mathematical models to data from questionnaires and tests as a basis for measuring abilities, attitudes, or other variables. It is used for statistical …
74Tikhonov regularization — Tikhonov regularization, named for Andrey Tikhonov, is the most commonly used method of regularization of ill posed problems. In statistics, the method is known as ridge regression, and, with multiple independent discoveries, it is also variously …
75Stochastic volatility — models are used in the field of quantitative finance to evaluate derivative securities, such as options. The name derives from the models treatment of the underlying security s volatility as a random process, governed by state variables such as… …
76Cochran's C test — In statistics, Cochran s C test [1], named after William G. Cochran, is a one sided upper limit variance outlier test. The C test is used to decide if a single estimate of a variance (or a standard deviation) is significantly larger than a group… …
77Opinion poll — An opinion poll, sometimes simply referred to as a poll is a survey of public opinion from a particular sample. Opinion polls are usually designed to represent the opinions of a population by conducting a series of questions and then… …
78Naegele's rule — is a standard way of calculating the due date for a pregnancy. The rule estimates the expected date of delivery (EDD) by adding one year, subtracting three months, and adding seven days to the first day of a woman s last menstrual period (LMP).… …
79Nonlinear regression — See Michaelis Menten kinetics for details In statistics, nonlinear regression is a form of regression analysis in which observational data are modeled by a function which is a nonlinear combination of the model parameters and depends on one or… …
80Restricted randomization — Many processes have more than one source of variation in them. In order to reduce variation in processes, these multiple sources must be understood, and that often leads to the concept of nested or hierarchical data structures. For example, in… …
