Percentile function

Use the Minitab calculator to calculate the sample percentile for a specified probability and set of numbers. Percentiles divide the data set into parts. Usually, the nth percentile has n% of the observations below it, and (100-n)% of observations above it.

To use this function, choose Calc > Calculator.

For example, in the following graph, 25% of the total data values lie below the 25th percentile (red region), while 75% lie above the 25th percentile (white region).

Syntax

PERCENTILE(number,probability)

Calculates the sample percentile, for a specified probability and number (the column containing the sample data). Missing values are ignored. The probability must be between 0 and 1, inclusive, and indicates the percentile. For example, to determine the 1st quartile (25th percentile) of a column of data, enter the column number and the probability 0.25.

Example

Column Calculator expression Result
C1 contains 2, 3, 5, and 7 PERCENTILE (C1,0.25) 2.25

Formula

Minitab's calculator uses the empirical percentile function for the PERCENTILE function.

Notation
TermDescription
p the percentage of data less than or equal to the desired percentile, divided by 100
Xy the yth row of the data when the data are sorted from least to greatest
ythe truncated value of w
wp(N+1)
Nthe number of rows with nonmissing data
zw-y