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Topic: Statistical distribution


  
  Statistical Distribution of Childhood IQ Scores
The distribution of IQ scores was found to have a standard deviation of about 16.
In a log-normal distribution of IQ scores, the logarithm of the IQ scores would be normally distributed.
The distribution may produce accurate results under normal circumstances, but factors such as chromosomal abnormalities in the general population severely affect the left half of the curve.
sweb.uky.edu /~jcscov0/ratioiq.htm   (815 words)

  
  Springer Online Reference Works
Statistical hypotheses, verification of), statistical estimation of probability distributions and their parameters, etc. The field of application of these deeper statistical methods is considerably narrower, since it is required that the phenomena themselves are subject to fairly definite probability laws.
Modes of statistical description, however, are of interest not just by themselves, but as a means of obtaining, from statistical material, inferences on the laws to which the phenomena studied are subject, and for obtaining inferences on the grounds leading in each individual case to various observed statistical distributions.
On the basis of mathematical statistics, statistical methods of research and investigation in queueing theory, physics, hydrology, climatology, stellar astronomy, biology, medicine, etc., were particularly intensively developed.
eom.springer.de /M/m062710.htm   (2133 words)

  
 Statistical Data Analysis   (Site not responding. Last check: 2007-10-22)
It is also an appropriate distribution for describing data corresponding to resonance behavior, such as the variation with energy of the cross section of a nuclear reaction or the variation with velocity of the absorption of radiation in the Mossbauer effect.
Statistical inference is refer to extending your knowledge obtain from a random sample from a population to the whole population.
The probability distribution of the statistic upon which the the analysis is based is not dependent upon specific information or assumptions about the population(s) which the sample(s) are drawn, but only on general assumptions, such as a continuous and/or symmetric population distribution.
www.iph.ufrgs.br /corpodocente/marques/cd/rd/arsham/opre330.htm   (16032 words)

  
 Home
Correlation and covariance are related statistics in that the correlation is the standardized form of the covariance, that is, covariance is a measure of the association in original units, whereas the correlation is the measure of association in standardized units.
In statistical modeling, it most usually occurs in expressions defining frequency or probability distributions in terms of their relevant parameters (such as mean and variance of normal distribution), or in statistical models describing the estimated effect of a variable or variables on a response.
Statistical inference Also called inductive statistics, statistical inference is a form of reasoning from sample data to population parameters; that is, any generalization, prediction, estimate, or decision based on a sample and made about the population.
www.ic.arizona.edu /~ce411/definitions.htm   (10480 words)

  
 Probability distribution - Wikipedia, the free encyclopedia
A probability distribution is a special case of the more general notion of a probability measure, which is a function that assigns probabilities satisfying the Kolmogorov axioms to the measurable sets of a measurable space.
The rectangular distribution is a uniform distribution on [-1/2,1/2].
The triangular distribution on [a, b], a special case of which is the distribution of the sum of two uniformly distributed random variables (the convolution of two uniform distributions).
en.wikipedia.org /wiki/Statistical_distribution   (1460 words)

  
 Statistical Distribution of Foveal Transverse Chromatic Aberration, Pupil Centration, and Angle Psi in a Population of ...
Statistical Distribution of Foveal Transverse Chromatic Aberration, Pupil Centration, and Angle Psi in a Population of Young Adult Eyes
The statistical distribution of sTCA was well fit by a bivariate Gaussian function with mean values which were not significantly different from zero in either the horizontal or vertical directions.
Although the measured variances of sTCA for horizontal and vertical directions were statistically different, this difference was slight and did not disrupt the excellent fit of the theoretical Rayleigh distribution to the experimental histogram as shown in Fig.
research.opt.indiana.edu /Library/StatDistribution/StatDistribution.html   (7165 words)

  
 What is statistical mean, median, mode, and range? - a definition from Whatis.com - see also: mean, median, average, ...
The mean of a statistical distribution with a discrete random variable is the mathematical average of all the terms.
The mean of a statistical distribution with a continuous random variable is the value of that random variable, denoted by the lowercase Greek letter mu (µ), such that the area under the probability density function curve to the left of µ is the same as the area under the curve to the right of µ.
For a distribution with a continuous random variable, the range is the difference between the two extreme points on the distribution curve, where the value of the function falls to zero.
searchdatacenter.techtarget.com /sDefinition/0,,sid80_gci1060882,00.html   (784 words)

  
 Statistical Distribution of Maximum Surface Displacement in Weakly Nonlinear Random Waves   (Site not responding. Last check: 2007-10-22)
Based on the second-order random wave theory, a joint statistical distribution of the sea surface displacement at a spatially fixed point and its time derivatives of order one and two are derived by using the characteristic function expansion method.
From the joint distribution derived, a statistical distribution of the maximum sea surface displacement then is determined.
The distribution is found to depend on the frequency spectrum of sea waves associated with the linear approximation and the second-order wave-wave interaction.
www.pubs.asce.org /WWWdisplay.cgi?9901096   (197 words)

  
 Undergraduate Courses - Statistical Science Department - SMU
Statistics and simple probability are introduced in terms of problems that arise in manufacturing; their application to control of manufacturing processes.
Subject matter is divided into two areas, simulation experiments and statistical software, and includes generating random deviates from various distributions, analysis of statistical algorithms, an introduction to UNIX, an introduction to S-Plus for data analysis and graphics, interfacing S-Plus to code written in C and/or FORTRAN, and managing and manipulating very large data sets.
Statistical methods of analysis of multivariate data, tests and estimation of multivariate normal parameters; Hotelling’s T2, discriminant analysis, canonical correlation, principal components, and factor analysis.
www.smu.edu /statistics/test/courses.asp   (1284 words)

  
 Statistical Tables on PocketGear.com   (Site not responding. Last check: 2007-10-22)
The binomial distribution is useful for describing distributions of binomial events, such as the number of males and females in a random sample of companies, or the number of defective components in samples of 20 units taken from a production process.
The negative binomial distribution is used when the number of successes is fixed and we're interested in the number of failures before reaching the fixed number of successes.
The hypergeometric distribution is described by three parameters: N, the total number of objects R, the number of objects of the first type and k the number of objects to be chosen.
www.pocketgear.com /software_detail.asp?id=16944   (596 words)

  
 Weibull distribution - Wikipedia, the free encyclopedia
The Weibull distribution is often used in the field of life data analysis due to its flexibility—it can mimic the behavior of other statistical distributions such as the normal and the exponential.
The Weibull distribution is often used in place of the normal distribution due to the fact that a Weibull variate can be generated through inversion, while normal variates are typically generated using the more complicated Box-Muller method, which requires two uniform random variates.
It is also a very popular statistical model in reliability engineering and failure analysis, while it is widely applied in radar systems to model the dispersion of the received signals level produced by some types of clutters.
en.wikipedia.org /wiki/Weibull_distribution   (727 words)

  
 SPC - Statistical Process Control - Page 1 of 5
The reason for this is that many physical, biological, and social parameters obey the normal distribution.
Aside from the fact that the normal distribution is frequently encountered in our day-to-day lives, the mathematics governing normal behavior are fairly simple.
To illustrate this in more tangible terms, imagine taking down the height of every student in a randomly selected Grade 5 class and plotting the measurements on a chart whose x-axis corresponds to the height of the student and whose y-axis corresponds to the number of students.
www.siliconfareast.com /spc.htm   (340 words)

  
 [No title]   (Site not responding. Last check: 2007-10-22)
The Poisson distribution is a model for the number of calls received in a fixed time period by a telephone exchange, for the number of homicide victims in a given city in a year, and in general for events in which there are a very large number of potential occurrences, each having very small probability.
The F distribution is the distribution of the ratio of two independent chi-squared distributions, each normalized by dividing by their degrees of freedom.
The T distribution is the distribution of the ratio of a standard Normal distribution and the square root of a chi-square distribution.
sunsite.queensu.ca /rmc/Stats/standard.html   (2640 words)

  
 BioMed Central | Full text | Statistical distributions of optimal global alignment scores of random protein sequences
The normal distribution also agrees well with the score distribution frequencies when the shape parameter of the gamma distribution is sufficiently large, for this is the scenario when the normal distribution can be viewed as an approximation of the gamma distribution.
Accurate statistical estimate for similarity searches for local alignments has been studied comprehensively [1-4], and the Gumbel distribution is used to estimate the statistical significance for local alignments [5].
Most of the score distributions of the RUS sequence set agree well with the gamma distribution, no matter what the sequence length is. Although there are occasions when no distribution agrees perfectly well with the score distribution, the three-parameter gamma distribution is still the closest to the empirical distribution (Figure 4).
www.biomedcentral.com /1471-2105/6/257   (3627 words)

  
 Statistical distribution of energy
The distribution of a fixed amount of energy among a number of identical particles depends upon the density of available energy states and the probability that a given state will be occupied.
The probability that a given energy state will be occupied is given by the distribution function, but if there are more available energy states in a given energy interval, then that will give a greater weight to the probability for that energy interval.
The distribution of energy between identical particles depends in part upon how many available states there are in a given energy interval.
hyperphysics.phy-astr.gsu.edu /hbase/quantum/disene.html   (325 words)

  
 Exponential, Failure Distribution, Gaussian, Generalized Gamma, Lognormal, pdf...Life Distribution Terms
While not as frequently used for modeling life data as other life distributions, the generalized gamma distribution does have the ability to mimic the attributes of other distributions such as the Weibull or lognormal, based on the values of the distribution's parameters.
While the generalized gamma distribution is not often used to model life data by itself, its ability to behave like other more commonly-used life distributions is sometimes used to determine which of those life distributions should be used to model a particular set of data.
A lifetime statistical distribution that is often used to model products in which physical fatigue is the prominent contributor to the primary failure mode.
www.weibull.com /knowledge/rel_glossary_ld.htm   (398 words)

  
 Statistical distribution of tumuli on pahoehoe flow surfaces: Analysis of examples in Hawaii and Iceland and potential ...
Statistical distribution of tumuli on pahoehoe flow surfaces: Analysis of examples in Hawaii and Iceland and potential applications to lava flows on Mars
Three distinct styles of flow emplacement are studied: (1) lava flows undergo inflation that changes as a function of space and time resulting in random spatial distributions of tumuli, (2) lava flows with preferred pathways result in systematic clustering of inflation features, and (3) established tubes or narrow pahoehoe flows produce chains of tumuli.
Comparison of the spatial distribution of tumuli on a portion of a lava flow at Mauna Ulu with the Poisson distribution indicates that tumuli are randomly distributed on the flow surface, typical of style one emplacement where small-scale topographic variability and low slope influence development of preferred pathways that evolve over time.
www.agu.org /pubs/crossref/2005/2004JB003564.shtml   (422 words)

  
 Art - Statistical Distribution and Balance   (Site not responding. Last check: 2007-10-22)
Paintings are said to be balanced even when most of the stuff/action is on one side of the canvas.
Statistical distribution is concerned with the numbers and sizes of objects in a composition whereas balance is concerned with their placement in space.
The aforementioned distribution is distribution over a mathematical curve which represents our probabilistic expectation of finding an object of size "x" within the area of the canvas which in turn is guided by our experience in everyday life, i.e.
ebtx.com /art/art06f.htm   (332 words)

  
 Earthquake slip distribution: A statistical model
The purpose of this paper is to interpret slip statistics in a framework of extended earthquake sources.
Using various assumptions on temporal earthquake occurrence, these distributions are synthesized to evaluate the accuracy of geologic fault slip determinations and to estimate uncertainties in long-term earthquake patterns based on paleoseismic data.
We demonstrate the application of the derived slip statistical relations by analyzing the slip distribution and history of the San Andreas fault at Wrightwood, California.
www.agu.org /pubs/crossref/2005/2004JB003280.shtml   (311 words)

  
 Statistical Distribution -- from Wolfram MathWorld
The distribution of a variable is a description of the relative numbers of times each possible outcome will occur in a number of trials.
Formally, a distribution can be defined as a normalized measure, and the distribution of a random variable
Radon measure (which is usually the case), then the statistical distribution is a generalized function in the sense of a generalized function.
mathworld.wolfram.com /StatisticalDistribution.html   (164 words)

  
 Statistical Functions
The statistical Builtins generate sequences of random numbers, each conforming to its specific distribution.
Unless you have specified a seed for the distribution as a non-negative integer, the sample set drawn from the distribution will not be replicable.
The LOGNORMAL function generates a series of random numbers that conform to a Log-Normal distribution (that is, the log of the independent variable follows a normal distribution) with a specified mean and standard deviation.
www.iseesystems.com /Helpv9/builtins/statistical_functions.htm   (999 words)

  
 Cartographic Communication, Section 6
Therefore, in mapping statistical data, the cartographer is always trying to strike a balance between remaining true to the underlying data distribution and generalizing the data sufficiently to reveal intrinsic spatial patterns.
Although these issues of statistical generalization can be applied to data that is to be symbolized by points, lines, and areas, this discussion will be developed around the mapping of areas in choropleth maps.
These may indicate to the reader the nature of the statistical distribution being displayed and the means by which it was classified.
www.colorado.edu /geography/gcraft/notes/cartocom/section6.html   (1519 words)

  
 Qudata.com - Statistical Calculator
The mean and variance of normal distribution are equal to sample mean and standard deviation.
Statistical Calculator allows to calculate a lot of statistical parameters of the sample (num, mean, sigma, etc.), that are defined in Glossary.
If skewness > 0 then the distribution is overbalanced to the right, if skewness < 0 then the distribution is overbalanced to the left.
qudata.com /online/statcalc   (612 words)

  
 Display of Statistical Distribution
Descriptive statistics are used to summarize the distribution of our data.
One case of particular concern is when the data is distributed into "two lumps" rather than the "one lump" cases we've considered so far.
We found that data clustered around 10 and 15; that is, there were lots of points in the range of 10 to 11 and 14 to 15, but fewer points in similar ranges (for example 12 to 13 or 7 to 8 or 17 to 18).
www.physics.csbsju.edu /stats/display.distribution.html   (2228 words)

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