TermAlpha

Definition"level of risk or significance"; the probability of rejecting the null hypothesis when it is true; the probability of making a Type 1 error

TermBar Chart

Definitiona graph in which the classes are reported on the horizontal axis and the class frequencies on the vertical axis. The class frequencies are proportional to the heights of the bars

TermCentral Limit Theorem

Definitionif all samples of a particular size are selected from any population, the sampling distribution of the sample mean is approximately a normal distribution. This approximation improves with larger samples.

TermCluster Sample

Definitiona population is divided into clusters using naturally occurring geographic or other boundaries. Then, clusters are randomly selected and a sample is collected by randomly selecting from each other.

TermAlternate Hypothesis

Definitiona statement that is accepted if the sample data provide sufficient evidence that the null hypothesis is false

TermBeta

Definitionthe probability of committing a Type II error

TermChebyshev's Theorem

DefinitionFor any set of observations (sample or population), the proportion of the values that lie within k standard deviations of the mean is at least 1- 1/k^2, where k is any constant greater than 1.

TermCoefficient of Correlation

Definitiona measure of the strength of the linear relationship between two variables.

TermCoefficient of Determination

Definitionthe proportion of the total variation in the dependent variable Y that is explained, or accounted for, by the variation in the independent variable X.

TermCollectively Exhaustive

Definitionat least one of the events must occur when an experiment is conducted.

TermConditional Probability

Definitionthe probability of a particular event occurring, given that another event has occurred.

TermConfidence Interval

Definitiona range of values constructed from sample data so that the population parameter is likely to occur within that range at a specified probability. The specified probability is called the level of confidence.

TermContingency Table

Definitiona table used to classify sample observations according to two or more identifiable characteristics.

TermCorrelation Analysis

Definitiona group of techniques to measure the association between two variables.

TermCritical Value

Definitionthe dividing point between the region where the null hypothesis is rejected and the region where it is not rejected.

TermDependent Variable

Definitionthe variable that is being predicted or estimated. It is scaled on the Y-axis.

TermDescriptive Statistics

Definitionmethods of organizing, summarizing, and presenting data in an informative way.

TermDiscrete Random Variable

Definitiona random variable that can assume only certain clearly separated values.

TermEmpirical Probability

Definitionthe probability of an event happening is the fraction of the time similar events happened in the past.

TermEmpirical Rule

Definitionfor a symmetrical, bell-shaped frequency distribution, approximately 68% of the observations will lie within plus and minus one standard deviation of the mean; about 95% of the observations will lie within plus and minus two standard deviations of the mean; and practically all (99.7%) will lie within plus and minus three standard deviations of the mean.

TermEvent

Definitiona collection of one or more outcomes of an experiment.

TermExperiment

Definitiona process that leads to the occurrence of one and only one of several possible observations.

TermFrequency Distribution

Definitiona grouping of data into mutually exclusive classes showing the number of observations in each class.

TermFrequency Table

Definitiona grouping of qualitative data into mutually exclusive classes showing the number of observations in each class.

TermHistogram

Definitiona graph in which the classes are marked on the horizontal axis and the class frequencies on the vertical axis. The class frequencies are represented by the heights of the bars and the bars are drawn adjacent to each other.

TermHypothesis

Definitiona statement about a population parameter subject to verification.

TermHypothesis Testing

Definitiona procedure based on sample evidence and probability theory to determine whether the hypothesis is a reasonable statement.

TermIndependence

Definitionthe occurrence of one event has no effect on the probability of the occurrence of another event.

TermIndependent Variable

Definitionthe variable that provides the basis for estimation. It is the predictor variable. It is scaled on the X-axis.

TermInferential Statistics

Definitionthe methods used to estimate a property of a population on the basis of a sample.

TermJoint Probability

Definitiona probability that measures the likelihood two or more events will happen concurrently.

TermLaw of Large Numbers

Definitionover a large number of trials the empirical probability of an event will approach its true probability.

TermLeast Squares Principle

Definitiondetermining a regression equation by minimizing the sum of the squares of the vertical distances between the actual Y values and the predicted values of Y

TermLevel of Significance

Definitionthe probability of rejecting the null hypothesis when it is true

TermMedian

Definitionthe midpoint of the values after they have been ordered from the smallest to the largest, or the largest to the smallest

TermMean Deviation

Definitionthe arithmetic mean of the absolute values of the deviations from the arithmetic mean

TermMode

Definitionthe value of the observation that appears most frequently

TermMultiplication Formula

Definitionif there are m ways of doing one thing and n ways of doing another thing, there are m x n ways of doing both.

TermMutually Exclusive

Definitionthe occurrence of one event means that none of the other events can occur at the same time

TermNull Hypothesis

Definitiona statement about the value of a population parameter developed for the purpose of testing numerical evidence

TermOutcome

Definitiona particular result of an experiment

TermParameter

Definitiona characteristic of a population

TermPermutation

Definitionany arrangement of r objects selected from a single group of n possible objects

TermPie Chart

Definitiona chart that shows the proportion or percent that each class represents of the total number of frequencies

TermPoint Estimate

Definitionthe statistic, computed from sample information, which is used to estimate the population parameter

TermPopulation

Definitionthe entire set of individuals or objects of interest or the measurements obtained from all individuals or objects of interest

TermProbability

Definitiona value between zero and one, inclusive, describing the relative possibility (chance or likelihood) an event will occur

TermProbability Distribution

Definitiona listing of all the outcomes of an experiment and the probability associated with each outcome

TermProportion

Definitionthe fraction, ratio, or percent indicating the part of the sample or the population having a particular trait of interest

Termp-Value

Definitionthe probability of observing a sample value as extreme as, or more extreme than, the value observed, given that the null hypothesis is true

TermRandom Variable

Definitiona quantity resulting from an experiment that, by chance, can assume different values

TermRandom Variation

Definitionthe sum of the squared differences between each observation and its treatment mean

TermRange

DefinitionLargest value - smallest value

TermRegression Equation

Definitionan equation that expresses the linear relationship between two variables

TermSample

Definitiona portion, or part, of the population of interest

TermSampling Error

Definitionthe difference between a sample statistic and its corresponding population oarameter

TermSampling Distribution of Sample Mean

Definitiona probability distribution of all possible sample means of a given sample size

TermSimple Random Sample

Definitiona sample selected so that each item or person in the population has the same chance of being included

TermStandard Deviation

Definitionthe square root of the variance

TermStandard Error of Estimate

Definitiona measure of the dispersion, or scatter, of the observed values around the line of regression

TermStatistic

Definitiona characteristic of a sample

TermStatistics

Definitionthe science of collecting, organizing, presenting, analyzing, and interpreting data to assist in making more effective decisions

TermStratified Random Sample

Definitiona population is divided into subgroups, called strata, and a sample is randomly selected from each stratum

TermSubjective Concept of Probability

Definitionthe likelihood (probability) of a particular event happening that is assigned by an individual based on whatever information is available

TermSystematic Random Sample

Definitiona random starting point is selected, and then every kth member of the population is selected

TermTest Statistic

Definitiona value, determined from sample information, used to determine whether to reject the null hypothesis

TermTotal Variation

Definitionthe sum of the squared differences between each observation and the overall mean

TermTreatment Variation

Definitionthe sum of the squared differences between each treatment mean and the grand or overall mean

TermType I Error

Definitionrejecting the null hypothesis when it is true

TermType II Error

Definitionaccepting the null hypothesis when it is false

TermVariance

Definitionthe arithmetic mean of the squared deviations from the mean

TermZ Value

Definitionthe signed distance between a selected value, designated X, and the mean, divided by the standard deviation