The following data (read the data down first and then over to the right) represent the weekly accounts receivable balance (in $1000) of a hardware distributor over a 30-week period.

128.703 120.649 126.215 129.426 135.816 125.131 131.122 121.774 125.367 121.076

119.848 127.251 153.923 125.658 122.172 129.268 122.912 125.351 130.572 116.875

122.587 127.677 132.364 130.950 118.662 131.902 132.220 128.522 132.270 122.671

1. Set up a (individuals) control chart on the accounts balance and a moving range chart (i.e. calculate the appropriate centerline and control limits). Plot the charts and supplement the individuals control chart with supplementary runs rules (i.e. apply the Western Electric runs rules for detecting non-random patterns on control charts). Note: Use the X-Y chart in Excel to plot the control charts.
2. Were there any out-of-control points identified in part (a)? If so, assume a special-cause explanation can be given to the associated point(s).
3. From the result of part (b), what are the appropriate prospective/trial limits for the charts?