121) For each of the following situations, indicate the program data editing technique that is appropriate to detect the error:
a. Calgary Mountain Equipment Company uses prenumbered sales orders. The company is not sure that it can account for all sales orders for the week of October 21, 200X.
b. The amount of a check in a vouchers payable program was negative.
c. A data entry clerk failed to complete customer address information in a batch of sales orders.
122) Describe how random-access file updating differs from sequential file updating.
123) Describe how a son-father-grandfather master file retention system works. Describe how a master file destroyed in an update can be restored using this retention system.
124) Discuss the components necessary to operate a real-time sales system.
125) What are the benefits of program data editing?
126) Discuss how batch totals are prepared and used. Explain how the use of batch totals and data transfer logs helps to establish segregation of duties between user departments and the data processing department.