How To Make A Frequency Distribution Table for Grouped Data

Hello guys! :)

Back again with me the handsome blogger. This time I will share about how to make the frequency distribution data table group. There are 6 steps to make table frequency distribution of data group, that is as follows :

The first step we surfey the data will be created table frequency distribution.
Determine the range.
Specify the number of classes for the table interval.
Determine the length of the interval class.
Set the lower limit of the first interval class.
Observe how many equal numbers, in each class and write in the tally column with the sign "|". And fill in the number of frequencies according to the number of tally.

To be more understanding, let's practice the 6 steps into the following example:

Example :

Suppose there are data values for 80 students, among them are:

80 80 70 68 90 92 80 70 63 76
49 84 71 72 35 93 91 74 60 63

48 90 92 85 83 76 61 99 83 88

74 70 38 51 73 71 72 95 82 70

81 91 56 65 74 90 97 80 60 66

98 93 81 93 43 72 91 59 67 88

87 82 74 83 86 67 88 71 89 79

82 78 73 86 68 75 81 77 63 75

Answer :

let's use the 6 steps above !

1. The first step we surfey the data will be created table frequency distribution.

The data have been surveyed when the problem is made, then the data are:

80 80 70 68 90 92 80 70 63 76
49 84 71 72 35 93 91 74 60 63

48 90 92 85 83 76 61 99 83 88

74 70 38 51 73 71 72 95 82 70

81 91 56 65 74 90 97 80 60 66

98 93 81 93 43 72 91 59 67 88

87 82 74 83 86 67 88 71 89 79

82 78 73 86 68 75 81 77 63 75

2. Determine the range.

Range can be determined by subtracting the largest data with the smallest data.

Range = the largest data - the smallest data
Range = 99 - 35

Range = 64

3. Specify the number of classes for the table interval

The number of classes can be searched by the formula:

The number of classes = 1 + 3.3 log n, n is the sum of frequency data.

The number of classes = 1 + 3.3 log 80
The number of classes = 1 + (3.3) (1.9031)
The number of classes = 7.2802

So we can create lists with the number of classes 7 or 8

4. Determine the length of the interval class

The length of the class interval can be searched by:

length of interval class = Range / number of classes
length of interval class = 64 / 7

length of interval class = 9.14

So the length of the class we can take 9 or 10.

5. Set the lower limit of the first interval class

The lower limit of the first class interval can be retrieved from the smallest data or data smaller than the smallest data. However, the difference of less than the length of the class and the first class should not have a frequency equal to zero.

So I take the lower limit of the first interval is 31

6. Observe how many equal numbers, in each class and write in the tally column with the sign "|". And fill in the number of frequencies according to the number of tally.