Mean ( 0 )
The average of all data points
Definition:
12.5
11.9
12.5
12.7
12.7
12.9
13.0
13.2
13.4
13.5
N = 10
Σx = 128.3
0 = Σx
         N
0 = 128.3
           10
0 = 12.83
Note that the median (12.8) and mean are very close to each other. This indicates good distribution of data points.