Question

6. Rector Public Accounting concluded that completion times for audits should be fairly standard. Ten audits are selected from all five of Rector’s storefront offices. Based on the results shown here, construct and interpret an R-chart and X-chart to determine whether completion times are in control.

Sample

              1      2      3      4      5

                               4.1      10.5    9.7      7.8     15.7

                               3.2      15.0   11.9      9.5      8.9

                               3.6      6.0     12.0     6.9      7.8

                               5.6      9.0      5.8      5.8      7.6

                               6.3      8.0      6.9      4.8      6.8

                               5.2      5.6     14.8     7.2      5.9

                               6.7      3.9     21.8     15.3     3.6

                               9.9      7.2     21.8     14.2     5.8

                               8.7      5.5     10.8     15.9     4.1

                               8.8      6.8     12.8     13.6     5.6

Please provide steps using a TI-84 Calc.

Answer 1