# 3.5.2.35 QCD3

## Description

This function returns a factor. (Quality Control D3 Factor)

It determines the 3-sigma lower control limit for R charts (Range of Sample Charts) from the average range when the sample size (or subgroup size) n is given.

The Lower Control Limit for R = (factor)*(Average Range).

The calculations for the factors are based on the normal distribution.

## Syntax

double QCD3(int n)

n

Sample size

## Return

Returns Quality Control D3 Factor.

## Examples

QCD3(11) = ; //returns 0.256, the factor for a sample size of 11