Computing statistical tolerance intervals in JMPHi,
I am looking into the calculation of one-sided tolerance intervals. Searching the documentation, I found the following paragraph:
Now, please correct me if I am wrong, but as I understand it:
- s is the standard deviation of the data samples
- is the sample mean
- n is the number of samples
- 1-α is the confidence
- t is the noncentral t inverse cumulative distribution function
- and finally is the inverse cumulative normal distribution
The reason I am asking is that I am having difficulties recreating the tolerance interval calculated by this method in matlab. Please let me know if there is something here that I got wtong. Thank you.
Re: Computing statistical tolerance intervals in JMPIt looks like you have it correct; for the one-sided case, g' can be calculated exactly (as shown in the documentation). For the two sided case, however, a variety of approximations are available and some are better than others. But, be warned, it is not the case that two one-sided tolerance intervals (lower and upper, respectively, each at 1-alpha/2 confidence) gives the same interval as a two-sided tolerance interval at 1-alpha confidence.
