Yes, see reply to katxt, but I have mean, stdev from historical data roughly normal.
... that thread was surprisingly enlightening. Thank you, I learned the difference between confidence interval and tolerance interval. In this instance, I want to be using a tolerance interval.
Definition of...
Yes I've tried it, the interval isn't that large in comparison to my limits. I don't have enough evidence to suggest it isn't normal...
In this case I have a two sided interval (upper and lower specification)
Upper: 24
Lower: 7.05
Below is from minitab, my mean and stdev come from historical...
Hi,
I'm using the tolerance interval function in minitab, my sample size is limited to 7 (the parts are expensive blah blah)
I've heard to be statistically significant a sample size of 30 is recommended but in practice how low can I go for sample size when using a confidence / tolerance...