A set of 12 data values from category C have a sum of 357 a

A set of 12 data values from category C have a sum of 357, a set of 15 data values from category D have a sum of 289, a set of 11 data values from category E have a sum of 158, and a set of 13 data values from category F have a sum of 98. Give the grand mean.

Solution

Total sum of the categories is : 357+289+158+98=902

Total number of data values is : 12+15+11+13= 51

So grand mean is (902/51)=17.6863