Interval Explorer for One Sample Variance

[#1]

I don't understand what the interval, lower and upper bound outputs for this explorer tool are - they don't seem to match the traditional chi^2 math you would do to calculate the CI of a stdev. "Interval" doesn't even seem to match the range between the upper and lower bound....

What are the units of interval width?

Are they dependent on the value of the standard deviation?

Is it a half width or a full width?

How do I use this to calculate a CI? I know it's not supposed to be symmetrical...

Please and thank you,

[#2]

Hi @Brian_Pimentel : You can find that information here (click on help button).

https://www.jmp.com/support/help/en/18.0/#page/jmp/margin-of-error-for-one-sample-variance.shtml#

There it says the width (full width since you chose the Interval option) as shown is the same as you expect with the assumption that the sample variance =1 (this makes sense because you haven't collected the data yet). So, in your case, if you then take a sample of size 27, the width  of the 95% CI for the Population Variance will be 1.258*Sample Variance.