Statistical ratios

thumb|upright=1.8|A depiction of prevalence In epidemiology, prevalence is the proportion of a particular population found to be affected by a medical condition (typically a disease or a risk factor such as smoking or seatbelt use) at a specific time. It is derived by comparing the number of people found to have the condition with the total number of people studied and is usually expressed as a fraction, a percentage, or the number of cases per 10,000 or 100,000 people. Prevalence is most often used in questionnaire studies.

measure of likelihood of an event when another event is known to have occurred

measure comparing the level of a searched signal to the level of background noise

relative standard deviation: standard deviation divided by the mean

in statistics and epidemiology

number of standard deviations by which the value of a raw score is above or below the mean

type of coefficient

thumb|An F-test pdf with d1 and d2 = 10, at a significance level of 0.05. (Red shaded region indicates the critical region) An F-test is a statistical test that compares variances. It is used to determine if the variances of two samples, or if the ratios of variances among multiple samples, are significantly different. The test calculates a statistic, represented by the random variable F, and checks if it follows an F-distribution. This check is valid if the null hypothesis is true and standard assumptions about the errors (ε) in the data hold.

statistical measures of the performance of a binary classification test

In probability theory, odds provide a measure of the probability of a particular outcome. Odds are commonly used in gambling and statistics. For example for an event that is 40% probable, one could say that the odds are or

in finance, number describing the correlated volatility of an asset in relation to the volatility of the benchmark

indicator for how well data points fit a line or curve

measure of an investment's risk premium

frequency with which an engineered system or component fails

percentage of people in a study or treatment group still alive for a given period of time after diagnosis

statistical test used for comparing the goodness of fit of two statistical models

ratio of the marginal likelihood of two statistical models

thumb|350px|Precision and recall In statistical analysis of binary classification and information retrieval systems, the F-score or F-measure is a measure of predictive performance. It is calculated from the precision and recall of the test, where the precision is the number of true positive results divided by the number of all samples predicted to be positive, including those not identified correctly, and the recall is the number of true positive results divided by the number of all samples that should have been identified as positive. Precision is also known as positive predictive value, and

percentage of the population that contracts the disease in an at risk population during a specified time interval

measure of financial risk

statistical procedure

measure of collinearity in statistical regression models

ratio of the hazard rates corresponding to the conditions described by two levels of an explanatory variable

type of coefficient

normalized central moments

Measurement in finance

in biostatistics, proportion of true positive and true negative results

statistics concept

statistical measure of association

normalized measure of the dispersion of a probability distribution

relative decrease in the risk of an adverse event in the exposed group compared to an unexposed group

measure of the relationship between the statistical dispersion within individual categories and the dispersion across the whole population or sample

Kind of ratio