Question

30 children were asked about the number of hours they watched TV programmes last week. The results are recorded as under: Number of hours 0-5, 5-10, 10-15, 15-20; Frequency 8, 16, 4, 2. Can we say that the number of children who watched TV for 10 or more hours a week is 22? Justify your answer.

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?

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.