Frequency Distribution Table

Frequency Distribution Table

Frequency Distribution Table

The frequency is the number of times of repetition of data. So the table which contains frequency and data is called a frequency distribution table or simply frequency table.

Frequency table for discrete data:

Example: Let’s observe the marks secured by 20 students in a math test of 20 marks.
10,       8,         9,         8,         10,       10,       11,       12,       14,    15,
8,         9,         7,         8,         10,       10,       11,       12,       10,    8

The frequency distribution table of the above data is given below:

Marks
Frequency
7
8
9
10
11
12
14
15
1
5
2
6
2
2
1
1

For group (continuous) data:

When the number of observation is a large amount of data which are converting into a compact form, we organize it in groups. These groups are called class intervals. We should make group or classes of the same size. The difference of the upper limit and lower limit of a group is called class size.

Consider the following data showing the marks of 30 students in the first term examination.

23, 29, 40, 15, 30, 35, 45, 48, 25, 5, 16, 22, 18, 33, 42, 46, 23, 36, 31, 26, 24, 37, 42, 20, 19, 41, 28, 38, 29, 17

Marks
Frequency
0 - 10
10 - 20
20 - 30
30 - 40
40 - 50
1
5
10
7
7

For a large number of data, to draw a frequency table, we should use the following steps:

Step 1 :Identify the smallest data and largest data.
Step 2 :Divide the data into an appropriate class interval in the same size
Step 3 :Common data always belongs to the higher class e.g. in 10-20 and 20-30, 20 lies in 20-30.
Step 4 :Count the data and write tally bars in a frequency table.

Cumulative frequency table

Cumulative frequency is a continuous frequency distribution in which frequencies are accumulated either in ascending or descending order. Look at the following example to be more clear about the cumulative frequency.

Marks
10
20
30
40
50
60
No. of students
2
5
4
7
3
6

Cumulative frequency table:

Marks
No of students (f)
Cumulative frequency (C.F.)
10
20
30
40
50
60
2
5
7
4
3
6
2
2+5=7
7+7=14
14+4=18
18+3=21
21+6=27

From the above table, it is clear that the cumulative frequency is the sum of the frequencies up to the corresponding class.


Workout Examples

Example 1: Represent the following data into a frequency distribution table.
                        15        10        16        9          7          8          9
                        10        15        10        8          4          7          8

Solution: Here,
                        Frequency distribution table,
                      
Data
Frequency
4
7
8
9
10
15
16
1
2
3
2
3
2
1


Example 2: Represent the following data into a frequency distribution table by making appropriate class interval.

4          7          12        15        50        22        25        27        29        33      39        44        47        18        51        31        20        21        41        36

Solution: Here,
                        Frequency distribution table,
                      
Data
Frequency
0-10
10-20
20-30
30-40
40-50
50-60
2
3
6
4
3
2


Example 3: Represent the following data into a cumulative frequency distribution table.

    8          7          9          16        10        10        12        15        15        12
    8          7          10        10        10        12        12        14        15        18

Solution: Here,
                        Cumulative frequency distribution table,
              
Data
Frequency
C.F.
7
8
9
10
12
14
15
16
18
2
2
1
5
4
1
3
1
1
2
2+2=4
4+1=5
5+5=10
10+4=14
14+1=15
15+3=18
18+1=19
19+1=20


You can comment your questions or problems regarding the frequency distribution table here.

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