Question

Students of Class XI obtained following marks in Economics. Classify the data in the form of individual series, discrete series, continuous series and cumulative frequency series.

15	15	18	16	20	21	25	25	15	16	18	22	24	25	20
18	22	24	24	25	25	23	20	15	16	17	19	18	22	22

Answer 1

Individual series is simply the arrangement of the given data in ascending (or, descending order)

15	15	15	15	16	16	16	17	18	18	18	18	19	20	20
20	21	22	22	22	22	23	24	24	24	25	25	25	25	25

Discrete series:


Continuous series:


Cumulative frequency series

Method1		Method2
Marks	No. of Students	Marks	No. of students
Less than 15 Less than 19 Less than 23 Less than 27	0 9 + 4 = 13 13 + 9 = 22 22 + 8 = 30	More than 12 More than 16 More than 20 More than 24	30 30 − 4 = 26 26 − 9 = 17 17 − 9 = 8