A random sample M1, M2,M3...M8 is taken from a population with unknown mean x. For each of the following, state wether or not it is a statistic, giving your reasons:

a) (M3+M8)/2

b) (Summation of Mi)/n

what interest would you have in the average of M3 and M8 ???

however the sum of all of them divided by n assuming that you use 8 for n is that mean that you might want to know.