Respuesta :

the mean of a collection of data, is basically the average of it

to find the average, add up all the values, and divide the total by how many values there are.

in your case:

mean = (12.5 + 13.23 + 11.2 + 14.5 + 12.5 + 13.23 + 15.6 + 15.75)/8
          = 13.56 (2d.p.)

hope that helps :)