95percentil

95percentil, commonly called the 95th percentile, is a statistical measure that indicates the value below which 95 percent of observations in a data set fall. It is a type of percentile, which divides a distribution into hundred equal parts and provides a way to describe the relative standing of a value within the data.

Calculation and estimation methods vary. In practice, data are first ordered from smallest to largest. Depending on the convention, the 95th percentile is obtained by locating a rank near p*(n+1) (where p = 0.95 and n is the sample size) and, if necessary, linearly interpolating between the two nearest values. Several percentile definitions exist, and different software packages may implement slightly different rules, especially for small samples or non-integer ranks.

Interpretation and uses. The 95percentil is a nonparametric summary that does not assume a particular distribution. It is widely used to flag high values, set thresholds for performance or safety, characterize distributions in growth or quality control, and summarize risk or exposure in various contexts. It provides a single benchmark point at which only 5 percent of observations exceed the value.

Relation to other measures. For a normal distribution, the 95th percentile corresponds roughly to mean plus 1.645 times the standard deviation, but this relation depends on the distribution and the chosen percentile method. Percentiles differ from measures like the mean or standard deviation and should be interpreted within the context of the data and method used to estimate them.

Example. In a small sorted dataset, different estimation rules yield 95percentil values around the upper end of the data, illustrating that the exact value depends on the method chosen. See also percentiles, quantiles, and quartiles.