Ppk results shown as asterisk after the transformation of Non-normal data

#1
Hi all,

I used Minitab 17 to calculated the Ppk of my 30 samples non-normal data and it's resulted as an asterisk for Ppk results in 1 set of data (The rest of data are include with both normal and non-normal and it's normally shown the Cpk/Ppk result in both normal and non-normal run). So I would like to ask if there any cause that make this data set failed to shown the Ppk results?

BTW my failed data set is as below:
#12
n = 30
Subgroup = 1
LCL = 5176.5
UCL = 5278.0
5240.6
5241.6
5241.8
5242.4
5242.0
5241.4
5240.4
5242.2
5242.2
5241.4
5242.2
5241.4
5241.6
5242.4
5243.4
5242.2
5239.0
5240.4
5241.4
5240.4
5238.2
5242.8
5237.2
5238.8
5239.2
5239.6
5237.4
5234.4
5237.1
5234.6

*FYI. for my failed run I used Weibull base on its p-value has the most fit distribution.

Thanks.
 
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