Regression Slope Test - Stat TrekTest method. Use a linear regression t-test (described in the next section) to
determine whether the slope of the regression line differs significantly from zero.

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Chi-Square Goodness of Fit Test - Stat TrekThis lesson describes when and how to conduct a chi-square goodness of fit test.
Key points are illustrated by a sample problem with solution.

one - sample t - test : Definition - Stat TrekDefinition of one - sample t - test , from the Stat Trek dictionary of statistical terms
and concepts. This statistics glossary includes definitions of all technical terms ...

Random Number Generator | Random Number Table - Stat TrekUse the Random Number Generator to create a list of random numbers, based
on your specifications. Create a random number table of up to ... What are random numbers? - What is a random number generator?

Random Number Generator - Stat TrekUse the Random Number Generator to create a list of random ... Numbers were
randomly selected from within the range of 0 to 99999. What are random numbers? - What is a random number generator?

Negative Binomial Distribution - Stat TrekIn this lesson, we cover the negative binomial distribution and the geometric
distribution. As we will see, the geometric distribution is a special case of the ...

Poisson Distribution - Stat TrekA Poisson distribution is the probability distribution of the outcomes from a
Poisson experiment. This lesson describes Poisson experiments and shows how
they ...

Matrix Rank - Stat TrekThis lesson defines matrix rank. It shows how the rank of a matrix is related to the
linear dependence among its vectors, and it shows how the rank of a matrix is ...

Element : Definition - Stat TrekDefinition of element , from the Stat Trek dictionary of statistical terms and
concepts. This statistics glossary includes definitions of all technical terms used
on Stat ...

T Distribution Calculator - Stat TrekThe t distribution calculator makes it easy to compute cumulative probabilities,
based on t ... Click the Calculate button to compute a value for the blank text box.

Statistics Notation - Stat TrekThis web page describes how symbols are used on the Stat Trek web site to
represent ... μ refers to a population mean; and x, to a sample mean . σ refers to
the ...

Chi - Square Distribution - Stat TrekThe distribution of the chi-square statistic is called the chi - square distribution .
This lesson shows how to compute the chi-square statistic and how to find the ...

Probability Calculator - Stat TrekThe probability of winning the 100-yard dash is 0.25, and the probability of ... is
defined, we enter the problem definition into the Probability Calculator. ... 34
Stories to Help You Actually Understand Statistics

Confidence Level : Definition - Stat TrekDefinition of confidence level , from the Stat Trek dictionary of statistical terms and
concepts. This statistics glossary includes definitions of all technical terms used ...

Measurement Scales - Stat TrekMeasurement scales are used to categorize and/or quantify variables. This
lesson describes four scales of measurement used in statistical analysis: nominal
, ...

Statistics , Probability, and Survey SamplingThis web site provides training and tools to help you solve statistics problems ...
AP and Advanced Placement Program are registered trademarks of the College ...

F -Distribution Calculator - Stat Trek? A probability is a number expressing the chances that a specific event will
occur. This number can take on any value ...

Matrix Algebra Tutorial - Stat TrekDetermine matrix rank (i.e., distinguish singular from non-singular matrices). Find
the determinant and inverse for any square matrix. Use matrix algebra to solve ...

This web site provides training and tools to help you solve statistics problems ...
Free statistics tutorials cover statistics , probability, and survey sampling - all ...

Experiments in Statistics - Stat TrekDescribes experiments . Covers independent variables (treatments, levels,
placebo) and dependent variables. Lists characteristics of a well-designed ...

Sample Size : Simple Random Samples - Stat TrekHow to find the smallest sample size that provides the required precision, given
simple random sampling. Includes sample problem to illustrate key points.

This web site provides training and tools to help you solve statistics problems
quickly, easily, and accurately - without having to ask anyone for help .

Stratified Sampling - Stat TrekThis lesson describes the use of stratified random sampling as a sampling
method. It covers both proportionate and disproportionate sample designs.
Includes ...

Statistics , Probability , and Survey SamplingThis web site provides training and tools to help you solve statistics problems ...
Free statistics tutorials cover statistics , probability , and survey sampling - all ...

Confidence Interval - Stat TrekSpecify the confidence interval . The uncertainty is denoted by the confidence
level. And the range of the confidence interval is defined by the following
equation .

Standard Error - Stat TrekThe standard error is an estimate of the standard deviation of a statistic. This
lesson shows how to compute the standard error , based on sample data. Also ...

Cumulative Frequency Plots - Stat TrekView video lesson on cumulative frequency plots ... From the graph , you can see
that about 25% of students received a score of 64 or less. ... ( D ) 50 inches

Standard Deviation : Definition - Stat TrekDefinition of standard deviation , from the Stat Trek dictionary of statistical terms
and concepts. This statistics glossary includes definitions of all technical terms ...

AP Statistics Practice Test - Stat TrekLike the actual exam , this practice exam has 40 multiple-choice questions ,
covering a variety of topics. Includes detailed solutions for all test questions .

Linear Regression - Stat TrekIntroduction to least-squares linear regression. ... Linear regression finds the
straight line, called the least squares regression line or LSRL, that best
represents ...

How to conduct a hypothesis test to determine whether there is a significant
linear relationship between an independent variable and a dependent variable.

Obtain cumulative probabilities and t scores from an on-line t distribution,
statistical table: ... Which random variable should I use - the t score or the sample
mean "? .... Statistics for People Who (Think They) Hate Statistics: Excel 2007
Edition

Hypothesis Tests - Stat TrekThis assumption may or may not be true. Hypothesis testing refers to the formal
procedures used by statisticians to accept or reject statistical hypotheses.

Influential Points in Regression - Stat TrekFor example, when the data set is very large, a single outlier may not have a big
effect on the regression equation. AP Statistics Tutorial . Exploring Data.

In general, capital letters refer to population attributes (i.e., parameters); and
lower-case letters refer to sample attributes (i.e., statistics ). For example,. P refers
to ...

Variables in Statistics - Stat TrekCovers use of variables in statistics - categorical vs. quantitative, discrete vs.
continuous, univariate vs. bivariate data. Includes free video lesson.

Chi - Square Calculator - Stat TrekThe chi - square distribution calculator makes it easy to compute cumulative
probabilities, based on the chi - square statistic. For help, read the Frequently-
Asked ...

AP Statistics Study Guides - Stat TrekReview of Study Guides: AP Statistics. Many books provide test -preparation help
for the AP Statistics exam . To identify the best study guide, Stat Trek evaluated ...

Statistics Problems With Solutions - Stat TrekProbability and statistics problems. Completely solved in ... Based on AP statistics
exam questions . ... The correct answer is B. The solution involves four steps.

Chi - Square Test of Independence - Stat TrekWe could use a chi - square test for independence to determine whether gender is
related to voting preference. The sample problem at the end of the lesson ...

Confidence Interval : Definition - Stat TrekDefinition of confidence interval , from the Stat Trek dictionary of statistical terms
and concepts. This statistics glossary includes definitions of all technical terms ...

A confidence interval describes the amount of uncertainty associated with a
sample estimate of a ... Often, the margin of error is not given; you must calculate
it.

Bayes Theorem (aka, Bayes Rule) - Stat TrekBayes ' theorem (also known as Bayes' rule) is a useful tool for calculating ... This
section presents an example that demonstrates how Bayes ' theorem can be ...

For example , suppose we wanted to determine whether a coin was fair and
balanced. A null hypothesis might be that half the flips would result in Heads and
half ...

Confounding : Definition - Stat TrekConfounding occurs when the experimental controls do not allow the
experimenter to reasonably eliminate plausible alternative explanations for an
observed ...

AP Statistics Calculator Comparison - Stat TrekReview of graphing calculators approved for use on the AP statistics exam and
on the AP ... Texas Instruments , TI -84 PLUS SILV, $114.89, $65.99, 4.5, 141.

Hypothesis Test for Mean - Stat TrekHow to conduct a hypothesis test for a mean value, using a one-sample t- test .
The test procedure is illustrated with examples for one- and two-tailed tests .

Margin of Error : Definition - Stat TrekDefinition of margin of error , from the Stat Trek dictionary of statistical terms and
concepts. This statistics glossary includes definitions of all technical terms used ...

F Distribution - Stat TrekThe f statistic , also known as an f value , is a random variable that has an F
distribution. (We discuss the F distribution in the next section.) Here are the steps
...

Boxplot (aka, Box and Whisker Plot) - Stat TrekHow to read and interpret boxplots (aka, box and whisker plots ). How to use
boxplots to display quantitative data. Includes free, video lesson on box and
whisker ...

How to conduct a chi-square goodness of fit test. The test ... From Stat Trek's free,
online statistics tutorial . ... The sampling method is simple random sampling.

Sampling Distribution - Stat TrekThe central limit theorem states that the sampling distribution of any statistic will
be normal or nearly normal, if the sample size is large enough. How large is ...

Statistics Formulas - Stat TrekTrek tutorials. Each formula links to a web page that explains how to use the
formula . .... Variance of a linear transformation = Var(Y) = a * Var(X).
Standardized ...

How to use sample data to test statistical hypotheses . Covers the null hypothesis ,
alternative hypothesis , decision rules, Type I error, Type II error, power, ...

Mean, Median, and Central Tendency - Stat TrekThe two most common measures of central tendency are the median and the
mean. ... Teach yourself statistics . Skip to ... View video lesson on central
tendency .

Mean of a linear transformation = E(Y) = Y = aX + b. Variance of a linear
transformation = Var(Y) = a * Var ( X ). Standardized score = z = (x - μx) / σx. t-score
= t = (x ...

Margin of Error - Stat TrekHow to compute margin of error for proportions and means. ... You can use the
Normal Distribution Calculator to find the critical z score, and the t Distribution ...