cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 
  • JMP will suspend normal business operations for our Winter Holiday beginning on Wednesday, Dec. 24, 2025, at 5:00 p.m. ET (2:00 p.m. ET for JMP Accounts Receivable).
    Regular business hours will resume at 9:00 a.m. EST on Friday, Jan. 2, 2026.
  • We’re retiring the File Exchange at the end of this year. The JMP Marketplace is now your destination for add-ins and extensions.

Discussions

Solve problems, and share tips and tricks with other JMP users.
Choose Language Hide Translation Bar
NewJMPUser1
Level I

jmp - Process behind how jmp calculates quartiles

I am new to jmp.  I have been using Analyze - Distribution to get the quartiles for a quantitative variable.

But when I went to double check jmp's process, I was confused.

I typed into jmp:

9 32 48 52 57 59 60 64 65 70

jmp tells me that Q1 is 44, but finding Q1 by hand and using my TI-84 gives me 48.  Also, jmp tells me Q3 is 64.25 when by hand it is 64.

Can someone tell me how jmp is calculating the quartiles behind the scenes?

Thanks!

1 REPLY 1
txnelson
Super User

Re: jmp - Process behind how jmp calculates quartiles

 

The JMP Online Help contains a page on the Statistical Details for Quantiles

     Help=>JMP Online Help

txnelson_0-1738725332775.png

You can also get there by using the "?" tool and click on the Quantiles report in the Distribution Platform's output

txnelson_1-1738725610882.png

Which will bring up 

txnelson_2-1738725686687.png

where you can click on the link and it will take you to the Statistical Details for Quantiles help page

I hope this gets you what you need

 

 

Jim

Recommended Articles