Use a control chart to analyze these data ...

     Q#Use a   control chart to analyze these data.If these expenditures are not in   control.what are the assignable causes?   Are there any periodic trends   in data(weekday versus weekend)?    

      date expenditure($)   1 22   2 24   3 20   4 18   5 20   6 20   7 28   8 23   9 25   10 20   11 18   12 17   13 19   14 29   15 24   16 24   17 21   18 18   19 18   20 20   21 29   22 22   23 24   24 20   25 21   26 20   27 19   28 28   29 24   30 23   31 21