Frequency Distribution:
While groups of numbers are organized, or ordered through some method, and put into tabular or graphic form, the result will display the "frequency distribution" of the data.
Example:
A test was given and the subsequent grades were received: the number of students receiving each grade is given in parentheses.
99(1), 98(2), 96(4), 92(7), 90(5), 88(13), 86(11), 83(7), 80(5), 78(4), 75(3), 60(1)
The data, as presented, is arranged in descending order and is referred to as an ordered array. But, as given, it is hard to determine any trend or other information from the data. Therefore, if the data is tabled and/or plotted some additional information may be acquired. While the data is ordered as display, a frequency distribution can be seen which was not apparent in the previous list of grades.
|
Grades
|
Number of
Occurrences
|
Frequency
Distribution
|
|
99
98
96
92
90
88
86
83
80
78
75
|
1
11
1111
11111 11
11111
11111 11111 111
11111 11111 1
11111 11
11111
1111
111
1
|
1
2
4
7
5
13
11
7
5
4
3
1
|
In short, one method of acquiring additional information from a set of data is to determine the frequency distribution of the data. A frequency distribution of any one data point is the number of times in that value occurs in a set of data. As will be elaborate later here, this will help simplify the calculation of other statistically useful numbers from a given set of data.