If I understand your interest correctly, I think Simulate ( https://www.jmp.com/support/help/en/17.1/#page/jmp/simulate.shtml# ) is what you need.
The idea is so sub-sample from your data and fit Lognormal repeatedly and collect summary statistics. I attach a modified Big Class sample data to illustrate.
Run the script in the data table. It fits Lognormal to "weight" variable, but use "random freq" as Freq.
Now right click on a statistic of interest, and choose "Simulate":
![peng_liu_0-1700056256302.png peng_liu_0-1700056256302.png](https://community.jmp.com/t5/image/serverpage/image-id/58727i6B2865F959CB4109/image-size/medium?v=v2&px=400)
In the dialog, choose "random freq" on both sides, click Ok:
![peng_liu_1-1700056302819.png peng_liu_1-1700056302819.png](https://community.jmp.com/t5/image/serverpage/image-id/58728i897F4B4A9EF0400C/image-size/medium?v=v2&px=400)
And you will get a table like the following:
![peng_liu_2-1700056368356.png peng_liu_2-1700056368356.png](https://community.jmp.com/t5/image/serverpage/image-id/58729i4D8EE9B17D77B4A0/image-size/medium?v=v2&px=400)
The last two columns are the summary statistics of individual fits to sub-samples.
The "random freq" column use "Resample Freq" function:
![peng_liu_3-1700059401364.png peng_liu_3-1700059401364.png](https://community.jmp.com/t5/image/serverpage/image-id/58731i282FFB209CD30646/image-size/medium?v=v2&px=400)
What you need to do is to tweak the threshold in the column formula, so you can get the total of 5/10/20 as you wish.
![peng_liu_4-1700059480327.png peng_liu_4-1700059480327.png](https://community.jmp.com/t5/image/serverpage/image-id/58732iCC7BC26FF6C1348B/image-size/medium?v=v2&px=400)