Question

Prepare a continuous grouped frequency distribution from the following data: Mid-point 5, 15, 25, 35, 45; Frequency 4, 8, 13, 12, 6. Also find the size of class intervals.

Convert the given frequency distribution into a continuous grouped frequency distribution: Class interval 150-153, 154-157, 158-161, 162-165, 166-169, 170-173; Frequency 7, 7, 15, 10, 5, 6. In which intervals would 153.5 and 157.5 be included?

Two sections of Class IX having 30 students each appeared for mathematics olympiad. The marks obtained by them are shown below: 46, 31, 74, 68, 42, 54, 14, 61, 83, 48, 37, 26, 8, 64, 57, 93, 72, 53, 59, 38, 16, 88, 75, 56, 46, 66, 45, 61, 54, 27, 27, 44, 63, 58, 43, 81, 64, 67, 36, 49, 50, 76, 38, 47, 55, 77, 62, 53, 40, 71, 60, 58, 45, 42, 34, 46, 40, 59, 42, 29. Construct a group frequency distribution of the data above using the classes 0-9, 10-19 etc., and hence find the number of students who secured more than 49 marks.

The following are the marks (out of 100) of 60 students in mathematics. 16, 13, 5, 80, 86, 7, 51, 48, 24, 56, 70, 19, 61, 17, 16, 36, 34, 42, 34, 35, 72, 55, 75, 31, 52, 28, 72, 97, 74, 45, 62, 68, 86, 35, 85, 36, 81, 75, 55, 26, 95, 31, 7, 78, 92, 62, 52, 56, 15, 63, 25, 36, 54, 44, 47, 27, 72, 17, 4, 30. Construct a grouped frequency distribution table with width 10 of each class starting from 0 - 9.