a) The annual income of five vice presidents of TMV industries are: $125000, 128000, 122000, $133000 and 140000

a) The annual income of five vice presidents of TMV industries are: $125000, 128000, 122000,
$133000 and 140000.
i. What is the population standard deviation? (5)
ii. The annual incomes of officers of another firm similar to TMV imdustries were also
studied. The mean was $129000 and the standard deviation $8612. Compare the means and
dispersion in the two firms. (2)

b. Suppose John, Niki and Marie are three graduate students of Economics. In one semester,
their mean marks of 4 courses are same, that is 72. However, standard deviation of their marks
are found to be as 0.05, 5.58 and 14.22. So, whose performance is less variable and more
consistent- John, Niki or Marie? Please explain your answer. (3)