NCERT Solutions for Class 6 Maths Chapter 9 Exercise 9.1

A data means information in the form of numerical figures.
Example:
The weights (in kg) of 10 students of a class are:
42, 36, 34, 45, 48, 52, 39, 40, 43, 47,
We call it the data related to the weights of 10 students of a class.

Data obtained in the original form is called raw data. Data given in the above examples are raw data.

Each numerical figure in a data is called an observation.

Arranging the numerical figures in an ascending or a descending order is called an array.

Arranging the data in a systematic form in the form of a table is called tabulation or presentation of the data.

The number of times a particular observation occurs is called its frequency.
Example:
Following are the number of members in 20 families in a village.
6, 8, 6, 3, 2, 5, 7, 8, 6, 5, 7, 5, 7, 6, 8, 7, 6, 6, 7, 5
Arrange the above data in an ascending order and then put it in the tabular form.
Ans: Arranging the data in an ascending order, we get the given data as
2, 3, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 8, 8, 8