In article , "MartinW" wrote:
Hi,

I had to google to find out what a Shewhart Chart is. OK now I know.
I've used them before just didn't know what they were called. <g

Jon Peltier shows you 2 techniques here on how to add horizontal lines.
http://peltiertech.com/Excel/Charts/AddLine.html

And here he explains how to add Standard Deviation and Mean lines.
http://peltiertech.com/Excel/Charts/RunChtLines.html

Jon uses a line chart in his example, however, I prefer to use an XY
scatter.
What you use depends on what you are analysing and also personal preference.

Also, if you want to see uneven x values (eg numbers of days) then XY
scatter is your only choice. All the other chart types even out the
intervals ... a serious trap for the unwary IMO ... or has this been fixed
in xl 2007 ?


" wrote in
message ...
working on a QA,QC project for a start up lab and I need some pointers on
stats, as well as how to construct these specific types of charts.