log normal model
81Pearson's chi-squared test — (χ2) is the best known of several chi squared tests – statistical procedures whose results are evaluated by reference to the chi squared distribution. Its properties were first investigated by Karl Pearson in 1900.[1] In contexts where it is… …
82Confidence interval — This article is about the confidence interval. For Confidence distribution, see Confidence Distribution. In statistics, a confidence interval (CI) is a particular kind of interval estimate of a population parameter and is used to indicate the… …
83Failure rate — is the frequency with which an engineered system or component fails, expressed for example in failures per hour. It is often denoted by the Greek letter λ (lambda) and is important in reliability engineering. The failure rate of a system usually… …
84Correlation 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 …
85Sample size determination — is the act of choosing the number of observations to include in a statistical sample. The sample size is an important feature of any empirical study in which the goal is to make inferences about a population from a sample. In practice, the sample …
86Moment (mathematics) — Second moment redirects here. For the technique in probability theory, see Second moment method. See also: Moment (physics) Increasing each of the first four moments in turn while keeping the others constant, for a discrete uniform distribution… …
87Unified neutral theory of biodiversity — The unified neutral theory of biodiversity and biogeography (here Unified Theory or UNTB ) is a theory and the title of a monograph [http://www.pupress.princeton.edu/titles/7105.html] by ecologist Stephen Hubbell. The theory aims to explain the… …
88Mean — This article is about the statistical concept. For other uses, see Mean (disambiguation). In statistics, mean has two related meanings: the arithmetic mean (and is distinguished from the geometric mean or harmonic mean). the expected value of a… …
89Contingency table — In statistics, a contingency table (also referred to as cross tabulation or cross tab) is a type of table in a matrix format that displays the (multivariate) frequency distribution of the variables. It is often used to record and analyze the… …
90Coefficient of variation — In probability theory and statistics, the coefficient of variation (CV) is a normalized measure of dispersion of a probability distribution. It is also known as unitized risk or the variation coefficient. The absolute value of the CV is sometimes …
