# Formula reference review

Original synthetic sample with deliberate errors. No customer data, native Dots test or OpenAI affiliation. The workbook is a review fixture, not an operational quality-control tool.

The stated rules require each row rate to use that batch’s own inspected count, totals to include all three batches, and the overall rate to divide total defects by total inspected.

## F1: Batches!D3

Observed: `=C3/B2`. 9 defective in batch B / 10 inspected in batch A = 0.9. Batch B inspected 90; 9 / 90 = 0.1.

Proposed: `=C3/B3`.

## F2: Summary!B2

Observed: `=SUM('Batches'!B2:B3)`. 10 + 90 = 100 omits batch C inspected count 100. Required total = 200.

Proposed: `=SUM('Batches'!B2:B4)`.

## F3: Summary!B4

Observed: `=AVERAGE('Batches'!D2:D4)`. Original mean (0.1 + 0.9 + 0) / 3 = 1/3. Even after fixing F1, the unweighted mean is 1/15, not required 10/200 = 0.05. Fix F2 before using B3/B2.

Proposed: `=B3/B2`.

Required total: 200 inspected, 10 defective, overall rate 5%. Correcting the row alone still leaves an unweighted 6.6667% rate. Apply all three proposals in order and recalculate in the buyer’s own suitable spreadsheet environment. No edited buyer workbook is delivered by this sample.

The original fixture was calculated and visually reviewed with Artifact Tool. The saved XLSX was independently inventoried without evaluating formulas. Five test methods cover exact saved formula evidence, independent arithmetic, active/external/XML rejection, duplicate/size bounds and malformed files. This verifies this original sample, not general spreadsheet correctness.

`inspect_xlsx.py` is a bounded, offline, static inventory helper. It uses Python standard libraries only. It never evaluates formulas, opens links, extracts members to disk or runs workbook macros. Cached values remain unverified. It rejects many unsupported workbook features, rather than claiming to support every XLSX. Input limits: 150 KiB compressed, 2 MiB expanded, 256 KiB per member, 100 ZIP members, 3 sheets, 2,000 cells and 50 plain formulas. Original test fixture includes an explicitly labeled reference column.

Sources: https://support.microsoft.com/en-us/excel/switch-between-relative-absolute-and-mixed-references and https://support.microsoft.com/en-us/excel/functions/sum-function .