1 [19 marks] In the frequency distribution of 100 NUST students given below, the number of students corresponding to expenditure groups 2040 and 6080 are missing from the table. Expenditure (per day) Frequency Cumulative Frequency 0 x 20 14 14 20 x 40 x 36 40 x 60 28 64 60 x 80 y 64 + y 80 x 100 15 79 + y 1.1 Find the values of x and y 1.2 Calculate the mean, median and mode 1.3 Calculate the coefficient of variation