Final answer:
A check digit is an effective control to reduce the likelihood of a transposition when entering an account number into a computer system. It helps in error detection by verifying that the entered number matches its calculated check digit.
Step-by-step explanation:
A control that can be used to reduce the likelihood of a transposition occurring when an account number is entered into a computer is a check digit. A check digit is an additional digit added to the end of a sequence of numbers that is calculated from the other digits. This allows the system to detect errors when numbers are entered manually. If the check digit does not match the calculated value, it indicates that there may have been a transposition or other data entry error.
For example, imagine an account number originally is 12345 and the calculated check digit is 6, so the number entered should be 123456. If a transposition error occurs and the sequence 12435 is entered, the system would calculate a different check digit and flag the error before it leads to a wrong account being accessed or incorrectly processed data.
Using check digits is a simple and effective way to improve data quality and reduce errors, and it is widely used in various industries, such as banking and inventory management, where accurate data entry is critical.