b) The marks obtained by 40 students in mathematics in examination are given below. Group the data into the class intervals of length 10 and construct a cumulative frequency distribution table.
42, 68, 80, 45, 92, 36, 8, 17, 49, 30
5, 26, 98, 74, 53, 65, 72, 28, 55, 46
86, 70, 62, 27, 16, 44, 85, 59, 51, 73
66, 78, 38, 81, 97, 77, 69, 45, 33, 67
