Source: https://guthlabs.ai/docs/instruments/hypothesis-test-calculator-t-test-z-test-chi2/qualification/

instrument qualification / verified-with-binding-errata

# Hypothesis Test Calculator (t-test/z-test/chi²) qualification

Verified with errata that must be applied at binding time.

Status: **VERIFIED_WITH_ERRATA**Lifecycle: **verified-with-binding-errata**

## Ledger verdict

Verified with errata that must be applied at binding time.

**Status**: VERIFIED_WITH_ERRATA

**Tranche**: tranche-6

**Review vectors**: 4

**Ledger rows**: 1

## Applied errata

````
[
  {
    "vector": 1,
    "field": "sample_standard_deviation/test_statistic/p_value",
    "wrong": "2 / 2 / 0.139326",
    "correct": "2.309401 / 1.732051 / 0.181690",
    "cause": "working computed s=sqrt(16/3)=2.309401 correctly, then wrote 'to make the stated t=2 exactly, s must instead be 2' and shipped the fabricated values — noticed-own-inconsistency-and-shipped family (t4-298)"
  }
]
````

## Adversarial re-test context

The full catalog was re-tested from boundary, convention, and self-check angles in 2,787 requests. Five genuine computational defects were independently verified and corrected. This page reports the current ledger state for this instrument; it does not imply product deployment or interface qualification.

## Release gate

Bind every attached correction, replay the affected vectors, enforce boundary validation, and preserve evidence before describing the executable surface as qualified.

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/hypothesis-test-calculator-t-test-z-test-chi2/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/hypothesis-test-calculator-t-test-z-test-chi2/mechanism/>)[03**Implementation**](<https://guthlabs.ai/docs/instruments/hypothesis-test-calculator-t-test-z-test-chi2/implementation/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `STRESS_TEST_RECEIPT.json`

- `tranche errata record`