Which of the following is false regarding evidence mix and design of the program? Audit procedures can be added or deleted as the auditor deems necessary. For some audit procedures, sample size, items to select, and timing cannot be changed however. The choice of which types of tests to use and how extensively they need to be performed can vary widely among audits for differing levels of internal control effectiveness and inherent risks. Because substantive analytical procedures are relatively inexpensive, many auditors perform them on all audits. Auditors must decide the preliminary judgment about materiality for the audit as a whole and then allocate the total to account balances, to establish performance materiality for each significant balance