Chapter 3 : Tables and Charts
Topics covered in this snacksized chapter:
The data or the information organized in the form of tables, charts and graphs are easy to understand.
It is often used to understand large amount of data and the relation between different parts of data.
Below is the representation of the data showing the number of marbles collected by a group of kids in tabular form.
Name
 Marbles Collected

John
 10

Eric
 15

Hannah
 22

Lisa
 7

It is clear from the table that the child who collected most marbles is Hannah and the child who collected least marbles is Lisa.
Charts are the way of representing data or information.
Charts can usually be read more quickly than the raw data.
The type of charts can include:
A Bar Chart is used to show comparison.
It is made up of a series of bars either arranged vertically or horizontally.
Example: A survey of 145 people revealed their favorite fruit:
Fruit
 People

Apple
 35

Orange
 30

Banana
 10

Kiwifruit
 25

Blueberry
 40

Grapes
 5

And here is the Bar Chart:
For that group of people Blueberries are most popular and grapes are the least popular.
A Chart that visually displays data using vertical bars, going up from the bottom, whose lengths are proportional to quantities they represent.
Bar Chart given below represents the total Sales for Atlanta, Paris and Sydney.
A Bar Chart in which the length of each bar is proportional to the quantity to be presented and all bars go across from left to right.
Below is the Horizontal Bar Chart that shows scores scored by team per season.
Circle graphs also known as Pie Charts, are generally used to show what percent of a whole each particular item in a group represents.
The graph shown below is called a pie chart:
Line Charts are typically used to show the change of something over time.
It also represents how two axes of information vary depending on one another.
Example: This line charts shows the midday temperature over a period of 7 days.
You can see at a glance that the temperature was at the peak on Monday, started to fall in the middle of the week and then rising again at the end of the week.
Raw data is the information that has not been processed in order to be displayed in any sort of presentable form.
Example: 24, 26, 24, 21, 27, 27, 30, 41, 32, 38
The frequency of a particular data value is the number of times the data value occurs.
For example, if 4 students have a score of 80 in mathematics, then the score of 80 is said to have a frequency of 4.
A frequency distribution is a tool for organizing data. We use it to group data into categories and show the number of observations in each category.
Example:
The marks awarded for an assignment set for a year 8 in the class of 20 students were as follows:
6, 7, 5, 7, 7, 8, 7, 6, 9, 7, 4, 10, 6, 8, 9, 5, 6, 4, 8, 8
Present this information in a frequency table.
Solution:
Marks
 Frequency

4
 2

5
 2

6
 4

7
 5

8
 4

9
 2

10
 1

The sum of the frequencies at or below a given value.
It is the running total of the frequencies up to the given value.
Example: The cumulative frequency table represents the volcanic eruptions between 1900 and 2000.
Relative Frequency is given by: Frequency/ Total Cumulative Frequency.
Example: Find the Relative Frequency of the data given below:
Class
 Frequency
 Cumulative Frequency

10 but < 20
 3
 3

20 but < 30
 6
 9

30 but < 40
 5
 14

40 but < 50
 4
 18

50 but < 60
 2
 20

Total
 20
 20
