feat : implemented interquartile_range and also added respective test…

[prateek-shanbhag]

… cases

Overview

1. This PR fixes or fixes part of Implement interquartile range #12 .
2. This PR implements interquartile_range and also added respective test cases

Essential Checklist

• The PR title starts with "Fix #bugnum: ", followed by a short, clear summary of the changes. (If this PR fixes part of an issue, prefix the title with "Fix part of #bugnum: ...".)
• "Allow edits from maintainers" is checked. (See here for instructions on how to enable it.)
• The PR is made from a branch that's not called "main/master".

Proof that changes are correct

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds an interquartile range (IQR) statistic to the primary module and verifies behavior with unit tests.

Changes:

• Introduces primary::interquartile_range implemented via existing quartiles(...).
• Re-exports interquartile_range from src/primary/mod.rs.
• Adds test coverage for empty, single-value, odd-length, and even-length datasets.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
tests/interquartile_range.rs	Adds unit tests covering basic IQR scenarios.
src/primary/mod.rs	Exposes the new interquartile_range module and re-export.
src/primary/interquartile_range.rs	Implements IQR by subtracting Q1 from Q3 using quartiles.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.