The following table gives the chest-girth of 30 men: Chest

The following table gives the chest-girth of 30 men: Chest girth (in cm) 50-54 55-59 60-64 65-69 70-74 75-79 80-84 85-89 90-94 Frequency 3 2 2 2 1 1 9 5 1 Calculate the mean chest girth of the group. (Hint: Convert the exclusive form into inclusive form by subtracting 0.5 from the lower limit and adding 0.5 to the upper limit of each class).