CITB HS&E / CSCS — Free Demo (10 Questions)

A design memorandum contains two valid equations but applies one outside its permitted range in a CITB HS&E / CSCS hard mock pre-calculation audit. Case focus: a field value is traceable but the reference datum used in the calculation is not. The issue is that the reported ladder inspection tag result changes sign when the reference datum is moved. For the Working at height item, which verification step must be completed before any numerical option can be trusted?