Final answer:
External, internal, and network security audits can all detect fraud and errors. External audits assess financial statements independently, internal audits review internal controls and processes, and network security audits examine information system security.
Step-by-step explanation:
All types of audits, external audits, internal audits, and network security audits, have the potential to detect fraud and errors within an organization. External audits are conducted by independent firms to provide an objective assessment of financial statements, which can unearth intentional misstatements or fraud. Internal audits, conducted by the organization's own audit staff, focus on reviewing internal controls and processes to identify weaknesses that could lead to fraud or errors. Network security audits specifically examine the security of an organization's information systems to identify vulnerabilities that could be exploited for fraud or lead to unintentional errors in data integrity.
Finding the probability of audits or being audited over a 20-year span would typically involve some understanding of the audit cycle for a specific individual or organization, which can vary widely. However, these calculations would be specific to the context provided and are not directly related to the types of audits that can detect fraud and errors.