Organisation of Data — Economics STD 11 Commerce — Question

There are two methods of classifying data according to class intervals, namely,

1. Exclusive method: Under this method, upper limit of the class is excluded. The upper limit of class interval is the lower limit of the next class, e.g.,

Marks	0 - 10	10 – 20	20 – 30
No. of Students	2	5	2

We include those students in first group whose marks are 0 or more but less than 10. If the marks of a student are 10, he is not included in the first group but in the second group, i.e., 10 - 20.

1. Inclusive method: Under this method, both the lower limit and the upper limit is included in the respective class, e.g.,

Marks	0 - 9	10 – 19	20 – 29
No. of Students	2	5	2

We include students in the first group whose marks are between 0 and 9. If the marks of a student are 10, he is included in the next group, i.e., 10 – 19.