Xbar/R control chart help (possibly a simple question)

Z

zitro

Guest
#1
Hi, I'm new to minitab and I'm having an issue. I am given a list of sample means which I compute in a minitab column. I am also given the corresponding sample ranges. There are 24 samples, each with n=5

So I go to "variable chart for subgroups", enter "5" for subgroup size, and this is where I have a problem: the chart has 5 points instead of 24, and I noticed that each point is a mean of 5 consecutive sample means. This is not what I want, I want a control chart for each sample mean.

I do not have this problem with attribute charts.
 

Miner

Forum Moderator
Staff member
Super Moderator
#2
Minitab expects the raw data (individual x's) to be entered instead of summary data (xbar's and R's). Minitab does have a macro available that will take summary data and create the chart.
 
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