Maths Chapter 04: Data Handling
Class 08 Maths NCERTThe information collected in all such cases is called data. Data is usually collected in the context of a situation that we want to study.
In your day-to-day life, you might have come across information, such as:
- Runs made by a batsman in the last 10 test matches.
- Number of wickets taken by a bowler in the last 10 ODIs.
- Marks scored by the students of your class in the Mathematics unit test.
- Number of story books read by each of your friends etc.
For example, a teacher may like to know the average height of students in her class. To find this, she will write the heights of all the students in her class, organise the data in a systematic manner and then interpret it accordingly.
Data mostly available to us in an unorganised form is called raw data. In order to draw meaningful inferences from any data, we need to organise the data systematically.
Frequency gives the number of times that a particular entry occurs.
Raw data can be ‘grouped’ and presented systematically through ‘grouped frequency distribution’. Grouped data can be presented using histogram. Histogram is a type of bar diagram, where the class intervals are shown on the horizontal axis and the heights of the bars show the frequency of the class interval. Also, there is no gap between the bars as there is no gap between the class intervals.
Data can also presented using circle graph or pie chart. A circle graph shows the relationship between a whole and its part.
There are certain experiments whose outcomes have an equal chance of occurring. A random experiment is one whose outcome cannot be predicted exactly in advance.
Outcomes of an experiment are equally likely if each has the same chance of occurring.