## Data and Variables

The resources below were chosen to align with the Clackamas Community College statistics curriculum.

 Topic Web page Video Other General Vocabulary Population STEPS Project, U of Glasgow Sample STEPS Project, U of Glasgow Statistics and parameters (web page) statisticshowto.com Exploratory Data Analysis US EPA website Types of Variables Intro to variables Scott Preston, SUNY-Oswego Categorical (qualitative) variables versus quantitative variables StatTrek Univariate vs. bivariate data StatTrek Categorical Variables (aka Qualitative or Nominal Variables) One-way frequency and relative frequency tables StatTrek Two-way tables (both frequency and relative frequency tables) StatTrek Excel video: Finding relative frequencies for one variable brucesimmons.com Excel video: Finding relative frequencies for a two-way table brucesimmons.com Graphs of Categorical Variables Graphs for one categorical variable (web page) StatTrek Graphs for one categorical variable (video) StatTrek Excel video: Bar graphs for one variable brucesimmons.com Excel video: Bar graphs for a two-way table brucesimmons.com Interactive web page: Graphing categorical variables onlinestatbook.com Cartoon, xkcd.com Quantitative Variables (aka Measurement Variables) Describing distributions: center, spread, shape StatTrek Describing distributions: skewness and modality StatTrek Central tendency concept onlinestatbook.com Calculating central tendency onlinestatbook.com Mean, median, mode Khan Academy Interactive web page: Central tendency and balance onlinestatbook.com Interactive web page: Exploring the mean and median Khan Academy Five-number summary and outliers Quartiles STEPS Project, U of Glasgow Quartiles and the five-number summary STEPS Project, U of Glasgow Excel video: Calculating the five-number summary brucesimmons.com Testing for outliers using the Tukey test brucesimmons.com Calculator video: one-variable stats on a TI calculator brucesimmons.com Cartoon making fun of TI calculators, xkcd.com Graphs of Quantitative Variables Dotplot StatTrek Stemplot StatTrek Histogram StatTrek Boxplot StatTrek Comparing data sets with graphs StatTrek Dotplot eHowEducation Stemplot onlinestatbook.com Histogram onlinestatbook.com Boxplot Khan Academy Calculator video: Boxplots on a TI calculator brucesimmons.com Interactive web page: Matching histograms to verbal descriptions University of Minnesota, Morris Cartoon: Outlier xkcd.com Variability (aka Spread or Dispersion) Calculating sample variance and sample standard deviation brucesimmons.com Calculating population variance and standard deviation Khan Academy Range, variance, and standard deviation Khan Academy Interactive web page: Matching standard deviations to graphs University of Minnesota, Morris Resistance and Nonresistance of Statistics Interactive web page: Is mean or median a better measure of center? onlinestatbook.com Interactive web page: Resistance of measures of center Beth Chance, Cal Poly San Luis Obispo Interactive web page: Resistance of measures of spread Beth Chance, Cal Poly San Luis Obispo Using the Standard Deviation Meausring position: percentiles, quartiles, and z-scores StatTrek Empirical rule (aka 68-95-99.7 rule) statisticshowto.com Computing z-scores Khan Academy Excel video: Computing z-scores brucesimmons.com Empirical rule and the normal distribution Khan Academy More practice with the empirical rule and the normal distribution Khan Academy Interactive empirical rule Beth Chance, Cal Poly San Luis Obispo Interactive practice problems for the empirical rule Khan Academy Sample and Population Standard Deviation: A Detailed Look Bias vs precision STEPS Project, U of Glasgow Interactive web page: Resistance of measures of spread Beth Chance, Cal Poly San Luis Obispo Topic Web page Video Other