Consider the population of 5 companies given below. Calculate the Mean and standard deviation for the above population. Select every possible sample of size 3. For example, ABC is one sample; ABD is another and so on. You will have a total of 10 samples. Calculate the average (mean, Xi ) for each of the samples. You will have 10 averages (X1 to X10). Calculate the average of these 10 sample means (call this overall mean, X ). Also calculate the standard deviation of these 10 sample means using the formula SD=10i=110(XiX)2