3. Suppose that the following data is the total annual incomes (rounded to thousands) for all 30 staffs in the Department of Mathematics of a university for the year 2014. Staff Annual Income(RM '000) Staff Annual Income (RM '000) 51 16 43 70 17 16 79 18 15 75 19 72 GUI D WN 72 20 92 5 5 21 25 25 22 30 38 23 24 74 24 46 54 25 47 26 46 12 15 27 45 13 56 28 38 14 17 29 81 15 77 30 49 Construct a grouped frequency distribution for the data using 5 classes. Calculate the relative frequency and percentage for all classes. Clue: The 5 classes are 15-30,31-46,47-62,63-78,79-94 a) What is thefrequency for the third class? b) What is the relative frequency for the second class? c) What is the percentage for the fifth class? d) Find the measurement of central tendency for this grouped of total annual incomes for all 30 staffs? a. Mean? b. Median? c. Mode? e ) What is the best measurement of central tendency for this data set? f) Find the measurement of variation for this grouped of total annual incomes for all 30 staffs? a. Variance? b . Standard deviation? C. Range g) What is the best measurement of variation for this data set