Answer:
20
Step-by-step explanation:
The sum of the ages of the first 12 is ...
12×18 = 216
The sum of the ages of the remaining 8 is ...
8×23 = 184
So, the sum of ages of all 20 people is ...
216 +184 = 400
and their average age is ...
400/20 = 20
The mean age of the members of the group is 20.
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The mean of a data set is the total of the values, divided by the number of values.
