Data-entry errors are more likely to occur when complex entries (such as 10-digit phone numbers) are made in
several different files or recur frequently in one or more files. In fact, the CUSTOMER file shown in Figure 1.5
contains just such an entry error: the third record in the CUSTOMER file has a transposed digit in the agent’s
phone number (615-882-2144 rather than 615-882-1244).