The frequency of a particular data value is the
number of times the data value occurs.
For example, if four students have a score of 80 in
mathematics, and then the score of 80 is said to have a frequency of
4. The frequency of a data value is often represented by f.
A frequency table is constructed by arranging collected data values
in ascending order of magnitude with their corresponding frequencies.
Example
The marks awarded for an assignment set for a Year 8 class
of 20 students were as follows:
6 7
5 7
7 8
7 6
9 7
4 10
6 8
8 9
5 6
4 8
Present this information in a frequency table.
Solution:
To construct a frequency table, we proceed as follows:
Step 1:
Construct a table with three columns. The first column
shows what is being arranged in ascending order (i.e. the marks). The
lowest mark is 4. So, start from 4 in the first column as shown below.
Step 2:
Go through the list of marks. The first mark in the
list is 6, so put a tally mark against 6 in the second column. The
second mark in the list is 7, so put a tally mark against 7 in the second
column. The third mark in the list is 5, so put a tally mark against 5
in the third column as shown below.
We continue this process until all marks in the list are
tallied.
Step 3:
Count the number of tally marks for each mark and write it
in third column. The finished frequency table is as follows:
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