Pre-numbered sales invoices are kept in a sales journal. The invoices are numbered from 0001 to 5000. a. Beginning in row 16, column 01, and proceeding horizontally in a table of random numbers (Table E.1), select a simple random sample of 50 invoice numbers. b. Select a systematic sample of 50 invoice numbers. Use the random numbers in row 20, columns 05–07, as the starting point for your selection. c. Are the invoices selected in (a) the same as those selected in (b)? Why or why not?