Inference App

[mcjtom]

I think there may be a display bug in all(?) hypothesis testing, when Alt. hypothesis is set to mju <> mju null (double tail). Try this:

Use the default example data for Z-test: 1 mju (reset Inference App. if needed), but change the Alt Hyp. to not equal. Plot screen looks like this:

   

Now, in Num screen, change Sample Mean to 0.539... (or anything greater than null Hyp mean). The screen should look about the same, but instead looks like this:

   

The p-value seems to be reported correctly - it's just the shaded area that is not. It seems to be the case with all test types with double tail Alt Hyp.

When I'm at it:

- the notation (red arrow in previous screen shot): it should probably read mju null not Sample Mean. Similarly in proportions there is: p, p-hat, and Pi null. Wouldn't two of them suffice?

- one improvement suggestion: in Plot screen the X-axis has dual scale (Z-score and actual mean values). If alpha button is checked, Critical Z range is reported on top of the screen but the actual critical values for the mean are not. They are available in the Results screen as Lower and Upper. I think being able to see them in Plot as well would be v. helpful in interpreting the results.