# 3.5.2.29 QCD2

## Description

This function returns a factor (Quality Control D2 Factor)

It estimates the standard deviation of a parent distribution (or population) from an average range when the sample size (or subgroup size) n is given.

The standard deviation of the parent distribution = average range/factor.

The returned factors assume sampling from a normal population.

## Syntax

double QCD2(int n)

n

Sample size.

## Return

Returns Quality Control D2 Factor.

## Examples

QCD2(4) =; // returns 2.05875, the Quality Control D2 factor for a sample size of 4