frequency distribution


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Related to frequency distribution: relative frequency, relative frequency distribution

frequency distribution

[¦frē·kwən·sē ‚dis·trə′byü·shən]
(mathematics)
A function which measures the relative frequency or probability that a variable can take on a set of values.
Frequency distributionclick for a larger image
Fig. 10 Frequency distribution.

frequency distribution

the number of times each value of a variable occurs in a set of observations.

A frequency-distribution table is a simple way of representing sociological observations. It consists of at least two columns: the left-hand one contains the values which a variable may take, and the right-hand one contains the number of times each value occurs. An additional right-hand column can also be included to show the percentage distribution. In Fig. 10 the number of male and female respondents to a questionnaire are shown. see also BAR CHART. HISTOGRAM. PIE CHART, which can also be used to represent distributions.

Frequency Distribution

 

a set of the various numerical values of some quantitative characteristic of the members of a population where an indication is given of the frequency of each value—that is, the size of the corresponding group of these members is indicated. A frequency distribution expresses the result of the grouping of the members of the population with respect to a single quantitative characteristic. If the values are ordered, that is, arranged according to increasing or decreasing magnitude, then the frequency distribution is said to be ranked.

A distinction is made between discrete and interval frequency distributions. A discrete frequency distribution is based on a discontinuously varying grouping characteristic; an example is the distribution of workers with respect to the number of machine tools operated. An interval, or grouped (that is, reduced to groups), frequency distribution is based on a continuously varying characteristic; an example of this type is the distribution of a group of people with respect to age. Frequency distributions can also be grouped in the case of a discrete characteristic if the range of this characteristic is sufficiently great—for example, the distribution of urban communities with respect to the number of residents.

The intervals of the grouping characteristic may be equal or unequal. If unequal, they usually increase progressively; this case arises when qualitatively different types of phenomena are being singled out. The sizes of the groups formed are indicated in the frequency distribution by absolute numbers, or frequencies; by relative numbers, or relative frequencies, which are usually percentages of the total; or by both, in two parallel columns. The ratios of the frequencies or relative frequencies to the sizes of the corresponding intervals are called the distribution density.

The importance of frequency distributions in statistics is great. A well-constructed frequency distribution makes possible a detailed analysis of the structure of the population with respect to a given characteristic. Thus, the groups into which the population breaks down can be determined. In addition, the nature of the distribution of the members of the population with respect to the given characteristic can be ascertained—for example, whether the distribution is symmetric or asymmetric or what the degree of concentration of the members is. Finally, various statistics can be calculated, such as the range of the characteristic (the absolute difference between the maximum and the minimum value), the average value of the characteristic, the deviations from the average value, the degree of skewness of the frequency distribution, and the measure of kurtosis (the degree of closeness of a cluster of values of the characteristic around the average value). For easy comprehension, a frequency distribution can be represented graphically in a rectangular coordinate system in the form of a frequency polygon, histogram, cumulative frequency polygon, or ogive. Various combinations of frequency distributions for a population can be presented in the form of statistical tables.

I. G. VENETSKII

References in periodicals archive ?
Another possible comparison between the Spanish versions of NWS and BCW could be made considering the frequency distributions of the phonemes that appear in those texts.
67%) Blood Frequency Distribution of Group Reference Population A 22% B 38% AB 8% O 32% Rh+ 96% Rh- 6% Table 2.
d4 the standard deviation of tR4, which could be achieved by simulation of homogeneous region, whose sites supposed to show a particular frequency distribution.
8) was tested with different frequency distributions.
Table 4: Frequency distribution of the respondents regarding to their family size (N=210)
TABLE 5: FREQUENCY DISTRIBUTION and LEVEL OF SIGNIFICANCE FOR ASSOCIATION BETWEEN YEAR OF STUDY AND DMFT (N=160)
Table 1: frequency distribution of studied sample in healthy group and group of epileptic patients according to the age.
The more important thing is a possibility for the frequency distributions to determine the most probable values of the functions describing various processes or objects; therefore, the most stable (preferred) states of these processes or objects can also be determined [3,4].
From the frequency distribution of self-esteem levels and trait coping styles of the undifferentiated group, regardless of score for self-esteem, most of the undifferentiated participants tended to employ negative coping styles (see Table 9).
When the percentage and frequency distribution of female and male athletes participated in the research in terms of injury areas are examined,it has been found that 8 female athletes in all are exposed to injury in reported areas and 1 (% 4,2),of these athletes is exposed to neck injury,1(%4,2) of them is to knee injury, 1(%4,2) of them is to right ankle, 1(%4,2) of them is to left ankle, 1(%4,2) of them is to right foot,3 of them (% 12,5) are to left foot area.
Looking at the frequency distribution figures from Table 1, the bending quality level is difficult to determine due to the inconsistent values.
89 carat stone in this limited sampling exercise is a positive sign for the diamond size frequency distribution of ON-K147/K148.

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