OpenChainGraph Suite · ART-693

ISA 530 Audit Sampling + MUS Calculator

Deterministic audit-sampling arithmetic in three functions you choose with the method field. Monetary unit sampling sizes the engagement: n = ceil(book_value × confidence_factor / (performance_materiality − expected_misstatement)) and sampling interval = round(book_value / n), failing closed when expected misstatement is not below performance materiality. Misstatement projection applies the tainting method to your sampled items and adds basic precision. The Benford screen compares your amounts' first-digit distribution against the expected proportions with a chi-square flag. The method's source standard is ISA 530, Audit Sampling (iaasb.org): this tool computes the arithmetic of the method; it never certifies compliance with the standard and never opines whether a sample is sufficient. It performs no selection logic and contains no randomness of any kind: where a selection start point is used, it is an input you declare, never a value generated here.

compliance_controlZero PIIClient-side onlyNo RNG
🔒 All inputs are processed locally in your browser. No data is transmitted. Do not enter real personal data — use synthetic or anonymised inputs only.
Scope & reliance
This page computes the arithmetic of the audit-sampling method whose source standard is ISA 530. It is not audit, legal, or compliance advice, and a computed figure is a deterministic function of the inputs you supply. Confidence factors, materiality thresholds, and sampled items are your inputs and your assertions; verify the method and its parameters against the current official text at iaasb.org before relying on any result. This node ships a zero-knowledge execution receipt bound to its published kernel (compute_proof_ready: ready), which is an execution proof rather than a formal correctness proof; see the proof-status note below the results.
Policy Parameters (JSON)
Result
Recomputation trace

      
Proof status
This node ships compute_proof_ready: ready. A Groth16 receipt over the risc0 zkVM attests that the published kernel, identified by its digest, produced the worked-example output; it proves that execution, not the correctness of the method for every input. The result above is a deterministic recompute of the same kernel, with a property-test floor over its other branches.

    

    

      
Execution Hash & §4 Artifact

      
SHA-256 execution hash (JCS canonical, RFC 8785). The sizing sample reproduces the worked example pinned in this node's build spec: 36492685d0d347c6…a62a1f.

      

      

      

        
        
      

    

  

  
  







  

    
Ask your agent

    
  

  
Copy this paragraph into Claude, OpenClaw, or any MCP-aware agent to run this exact tool, with this sample, and verify the artifact.

  
Run the AINumbers MCP tool `compute_isa530_audit_sampling_mus`. Task: Deterministic audit-sampling arithmetic: MUS sample size and interval, tainting-method misstatement projection with basic precision, and a Benford first-digit chi-square screen
Call it with arguments: {"policy_parameters":{"method":"monetary_unit_sampling","book_value":5000000,"performance_materiality":250000,"expected_misstatement":50000,"confidence_factor":3}}
Verify before trusting: call `verify_execution_hash` on mcp.ainumbers.co (https://mcp.ainumbers.co/mcp) with the parameter `claimed_hash` set to the returned `execution_hash`, passing the full artifact the run returned (the object containing `policy_parameters` + `output_payload` + `execution_hash`; equivalently `policy_parameters` + `output_payload` with `claimed_hash`), not the bare hash string.
Return the ledger link https://ledger.ainumbers.co/ so a human can re-verify without contacting us.
PII rule: All inputs are processed locally in your browser. No data is transmitted. Do not enter real personal data — use synthetic or anonymised inputs only.
Open the tool with the sample prefilled: https://ainumbers.co/chaingraph/art-693-isa530-audit-sampling-mus.html#p=v1.H4sIAAAAAAAA_wGNAHL_eyJtZXRob2QiOiJtb25ldGFyeV91bml0X3NhbXBsaW5nIiwiYm9va192YWx1ZSI6NTAwMDAwMCwicGVyZm9ybWFuY2VfbWF0ZXJpYWxpdHkiOjI1MDAwMCwiZXhwZWN0ZWRfbWlzc3RhdGVtZW50Ijo1MDAwMCwiY29uZmlkZW5jZV9mYWN0b3IiOjN9EGucuo0AAAA