In the office of the First National Bank there are five automatic cashiers (ATM's). Last week each of the automatic cashiers committed the following number of errors: 2,3,5,3 and 5.
a) How many different samples of two automatic cashiers are possible?
b) Write all the possible samples of size 2 and calculate the average or median of each one.
c) Calculate the average or the median of the average or medians of the samples and compare it with the average of the population.