Stats: Chi-Square Distribution
The chi-square ( ) distribution is obtained from the values of the ratio of the sample
variance and population variance multiplied by the degrees of freedom. This occurs
when the population is normally distributed with
popul
Stats: One-Way ANOVA
A One-Way Analysis of Variance is a way to test the equality of three or more means
at one time by using variances.
Assumptions
The populations from which the samples were obtained must be normally or
approximately normally distribute
Stats: F-Test
Definitions
F-distribution
The ratio of two independent chi-square variables divided by their respective
degrees of freedom. If the population variances are equal, this simplifies to be
the ratio of the sample variances.
Analysis of Variance
Statistics: Introduction
Definitions
Statistics
Collection of methods for planning experiments, obtaining data, and then
organizing, summarizing, presenting, analyzing, interpreting, and drawing
conclusions.
Variable
Characteristic or attribute that can a
Statistics: Frequency Distributions & Graphs
Definitions
Raw Data
Data collected in original form.
Frequency
The number of times a certain value or class of values occurs.
Frequency Distribution
The organization of raw data in table form with classes and
Stats: Two-Way ANOVA
The two-way analysis of variance is an extension to the one-way analysis of variance.
There are two independent variables (hence the name two-way).
Assumptions
The populations from which the samples were obtained must be normally or
a
Statistics: Introduction
Population vs Sample
The population includes all objects of interest whereas the sample is only a portion of
the population. Parameters are associated with populations and statistics with samples.
Parameters are usually denoted us
Stats: Measures of Central Tendency
The term "Average" is vague
Average could mean one of four things. The arithmetic mean, the median, midrange,
or mode. For this reason, it is better to specify which average you're talking about.
Mean
This is what peopl
Stats: Measures of Variation
Range
The range is the simplest measure of variation to find. It is simply the highest value
minus the lowest value.
RANGE = MAXIMUM - MINIMUM
Since the range only uses the largest and smallest values, it is greatly affected b
Stats: Measures of Position
Standard Scores (z-scores)
The standard score is obtained by subtracting the mean and dividing the difference by
the standard deviation. The symbol is z, which is why it's also called a z-score.
The mean of the standard scores
Stats: Test for Independence
In the test for independence, the claim is that the row and column variables are
independent of each other. This is the null hypothesis.
The multiplication rule said that if two events were independent, then the probability
of
Stats: Single Population Variance
The variable
has a chi-square distribution if the population variance has
a normal distribution. The degrees of freedom are n-1. We can use this to test the
population variance under certain conditions
Conditions for test
Stats: Goodness-of-fit Test
The idea behind the chi-square goodness-of-fit test is to see if the sample comes from
the population with the claimed distribution. Another way of looking at that is to ask if
the frequency distribution fits a specific pattern