If the risk of material misstatement is low $($e$.$g$.,$ the combined inherent risk and control risk assessments are low$)$

then the auditor needs more assurance from substantive procedures, and the auditor can reasonably accept a higher level of

assurance from substantive procedures and use greater sample sizes for substantive testing.

then the auditor should consider lowering the engagement fees.

then the auditor does not need as much assurance from substantive procedures, and the auditor can reasonably accept a

lower level of assurance from substantive procedures and use smaller sample sizes for substantive testing.

then the auditor would set audit risk at the highest possible level.