# Data Handling Class 8 Notes- Chapter 5

## What is Data handling?

Data handling is referred to the procedure done to organize the information provided in order to perform mathematical operations on them.

There are various components of data, we will be seeing those below:

• Raw Data– If the information which is provided is in an unorganized manner, then it is referred to as raw data. The organization of data is very important in order to have meaningful interference. The raw data can be represented properly with the help of grouped frequency distribution.
• Frequency– The value which we need to calculate the operations can exist multiple times which is known as frequency.

### What is a Histogram?

The data after grouping can be graphically represented with the help of histogram. It is a type of bar graph where the horizontal axis has the class intervals and the height of the bars shows the frequency of class interval and there are no gaps between the class intervals.

### What is a Pie Chart?

If the information required to show the relationship between the part with the whole, then the usage of circle chart or pie chart will be helpful.

### What is a Random Experiment?

There are chances that a certain amount of experiments have outcomes which have a similar number of chances of occurring and those events are put into the category of ‘equally likely’. But, in the case of a random experiment, the outcome cannot be predicted exactly prior to the event.

### What is the Probability of an Event?

When the outcomes fall into the category of equally likely, then probability is defined as

$Probability=\frac{Number of Outcomes leading to the event}{Total outcomes of the experiment}$

### Important Questions

1. A survey was made to find the type of music that a certain group of young people liked in a city. The adjoining pie chart shows the findings of this survey.

Answer the following questions according to the survey conducted about the young people taste in music. From this pie chart answer, the following:

• (i) How many young people were surveyed, if 20 people liked classical music?
• (ii) The maximum number of people liked which type of music?
• (iii)How many cassettes cassette company makes if it produces 1000 CD’s?