Re: Calculation of UCL/LCL for X Bar & R charts for n>>10

[GrantBlair@aol.com]

In a message dated 2/8/2003 6:16:42 AM Eastern Standard Time,=20
Kanedl@ldschurch.org writes:
>>>>I have an automatic monitor that samples at 100%, so my
sample count (n) is very large (300-6000.=A0 How to I=20
calculate UCL and LCL for XBar and R charts.=A0 I only have a=20
table for sample sizes of 2-10, and I do not have the=20
actual formula to allow me to scale to large sample sizes.<<<<


Use factors for an individuals chart. In addition to the individuals chart,=20
You should also display the moving range chart, unless your monitor=20
automatically calculates sigma....if it does, than also plot a sigma chart.=20

If you're 100% sampling, usually  these charts show special cause. That's=20
another discussion...let me know if that's the case.

Grant Blair
96 SC
GrantBlair@aol.com