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1. A sample of annual salary (in thousand dollars) is as follows: 34, 27, 303, 35, 50, 33, 34, 210, 20, 138, 38, 28 50 a) Find sample mean. b) Find the sample median. c) Find the first, third quartiles and IQR. d) What aspect of the data does IQR measure? State the advantage of using IQR relative to standard deviation? e) Construct a box plot. Mention a reason that box plot is useful