Sampling (MUS)
Justify statistically why testing high-risk items plus a smaller systematic sample is sufficient.
- General ledger alone
What it checks
- Above TE: 100% examined.
- High-risk scored: 100% examined.
- Residual low-risk: MUS interval-based sample.
- Evaluation on the upper misstatement limit, never on the errors found.
How the result is read
MUS samples the currency unit, so larger items are likelier to be picked. A clean sample does not establish that the untested remainder is clean — only that the upper limit on it is basic precision, and the conclusion holds only where that limit is below TE. The threshold throughout is TE — tolerable error, off the engagement materiality record — and not overall materiality. ISA 530 calls it tolerable misstatement; it is the same figure, and the workbook uses one name for it.
The worksheet, on the demo engagement
Sampling (MUS), as the application draws it for Harrow Precision Engineering Ltd, the fictional demo engagement — one row per stratum, plus the evaluation rows.
- Method
- Monetary-unit
- Confidence
- 95%
- Tolerable error (TE)
- 250
- Reliability factor
- 3.0 @ 95%
ISA 530. Above-TE and high-risk items are examined in full; only the residual is sampled, monetary-unit, from a random start below the achieved interval.
Result grid4 rows
| Stratum | Value | Items | Selection basis | Tested |
|---|---|---|---|---|
| Above TE — examined in full | 18,900 | 214 | Examined in full | 214 items |
| High risk — examined in full | 9,200 | 22 | Examined in full | 22 items |
| Residual — sampled | 17,000 | 501 | MUS, interval 83 = residual value ÷ n (204), random start below the interval | 204 items |
| Negative / nil — outside MUS | (1,400) | 18 | Own stratum — MUS selects proportional to value and cannot reach these | separate approach required |
In the application
Sampling (MUS) is filed under Completion, index letter L. "Run all analyses" runs it with every other analysis the ledger can answer. The worksheet states the population it tested on its face — or "Not applicable" with the reason when a column it depends on is empty — and the Excel workbook the engagement exports files it under L, beside an index of the source files with their SHA-256 fingerprints.
Read it with
Run your next audit file test without the Excel crash.
One free engagement to evaluate, valid 60 days. The ledger never leaves the machine.
- 20 minutes
- Runs on a fictional engagement
- No client data required