1. Tables
A table can be used to display pieces of data about different things. Tables, in statistics, are a way of showing your information or data. They use rows (horizontal) and columns (vertical). A table also usually looks like a grid, with information and data being put inside the cells. The heading of the table tells us what data is in each column and row.
1.1 Solved Example:
The table below shows activities done by a number of adults and children.
| Activity |
Cycling |
Swimming |
Debating |
Total |
| Number of children |
12 |
18 |
8 |
38 |
| Number of adults |
15 |
7 |
22 |
44 |
| Total |
27 |
25 |
30 |
82 |
From the table, it can be seen that there were 38 children and 44 adults participating in three different activities.
Let us now try to answer some questions using the above table,
a) How many children participated in debating?
Solution:
Looking at the number of children row and debating column,
8 children participated in debating.
b) How many adults participated in cycling and swimming?
Solution:
Looking at the number of adults row and cycling column,
15 adults participated in cycling.
Looking at the number of adults and swimming column,
7 adults participated in swimming.
Total = 15 + 7 = 22
22 adults participated in cycling and swimming.
1.2 Two-way tables
Many times more than one category of data is collected. For example, data collected on children at a school may include their favourite subject and their year group as another. Two-way tables are a way of sorting data so that the frequency of each category can be seen quickly and easily.
For example:
Below are twelve cards from a game:
The two way table shows a number of cards with patterns more than 2 different types.
|
Red |
Green |
| Triangle |
4 |
1 |
| Circle |
2 |
5 |
1.3 Two way tables - Solved Example
Complete the following table about a group of children to work out the total number of girls in the group:
|
Right-handed |
Left-handed |
Total |
| Boys |
19 |
|
|
| Girls |
|
7 |
|
| Total |
|
16 |
60 |
Solution:
Total left-handed = 16
Left-handed (Boys + Girls) = 16
Left-handed Boys + 7 = 16
Left-handed Boys = 16 - 7
Left-handed Boys = 9
Total no. of Boys = Right-handed Boys + Left-handed Boys
= 19 + 9
= 28
Total no. of Girls = Total no. of Students - Total no. of Boys
= 60 - 28
= 32
Right-handed Girls = Total number of girls - Number of left-handed girls
= 32 - 7
= 25
Total Right-handed = 19 + 25 = 44
|
Right-handed |
Left-handed |
Total |
| Boys |
19 |
9 |
28 |
| Girls |
25 |
7 |
32 |
| Total |
44 |
16 |
60 |
Here we have used different operations like addition, and subtraction to get the missing values in the table.
