Is anyone down to
really need it!

Alright, the mean is the sum of the ages divided by the number of peoplpe

ok, so example

let's say he has 3 people on his team (not realistic but it's an example)
4yr and 7yr and 4yr
3 people

4+7+7=15
15/3=5, mean is 5

if the 7yr old leaves and is replaced witha 6 year old
4+6+4=14
14/3=4.6666666666666666666666666666667
the mean is no longer 5 because one of the values changed