The ages (in years) of men selected from a community are as follows:

                        44   28   58   50   93   35   34   52   57   61
                        40   63   90   67   64   56   51   82   73   43
                        73   73   44   71   95   52   71   25   35   79
                        28   40   72   88   82   63   53   48   98   65
                        63   44   73   70   68   46   54   62   41   70

(a)        Prepare a group frequency distribution table with the intervals 20 – 29, 30 – 39, ...
(b)        Calculate the mean deviation of the distribution.