Option A: ChatGPT: computes the intervals and lays out the table
Best when: One conversation computes and lays out the table
What it does: ChatGPT computes; you check every number
Strong at: You can specify columns, calculations and groupings
Limit: Spreadsheet ceiling about 50 MB; split large exports
Free plan: Yes, limited (uploads, images, voice, data analysis)
Option B: Julius AI: computes the intervals and drafts the table
Best when: A data tool does the arithmetic and the first draft
What it does: Julius AI computes and drafts; you check numbers
Strong at: Accepts CSV and Excel uploads for analysis
Limit: Files stored for only 7 days on Free, Plus and Business
Free plan: Yes, limited (7-day file storage)
Option C: Claude: computes the intervals, two people check
Best when: Claude computes and drafts; two people check numbers
What it does: Claude computes and drafts; reviewers check
Strong at: Chats, writes, analyses data and codes
Limit: Interval arithmetic not evidenced; recompute a sample
Free plan: Yes, limited (usage caps)