Univariate Distributions

• How Random is Random?

This site is a tutorial that takes students through a mayoral election process while discussing the concept of randomness. Topics include margin of error and confidence levels.
• Dataset: Rock Fries Your Brains

This exercise uses descriptive statistics to analyze a data set about how rats respond to rock music vs. classical music.
• The Statistics of Hiring

This short article discusses how the comparative ratios of the tails of normal distributions can result in bias in hiring practices. It contains a link to an applet that shows the comparative tail probability ratios.
• Program for Statistical Analysis: PSPP

PSPP is a statistical analysis program. It is an upwardly compatible replacement of the proprietary statistical analysis program called SPSS. PSPP is a program for statistical analysis of sampled data. It interprets commands in the SPSS language and produces tabular output in ASCII, HTML, or PostScript format.

• Star Library: Histogram Sorting

This activity provides students with 24 histograms representing distributions with differing shapes and characteristics. By sorting the histograms into piles that seem to go together, and by describing those piles, students develop awareness of the different versions of particular shapes (e.g., different types of skewed distributions, or different types of normal distributions), that not all histograms are easy to classify, that there is a difference between models (normal, uniform) and characteristics (skewness, symmetry, etc.). Key words: Histogram, shape, normal, uniform, skewed, symmetric, bimodal
• The Cereal Box Problem: A lesson in expected value

Poses the following problem: Suppose there was one of six prizes inside your favorite box of cereal. Perhaps it's a pen, a plastic movie character, or a picture card. How many boxes of cereal would you expect to have to buy, to get all six prizes?

• The Cliff-Hanger

An applet explores the following problem: A long day hiking through the Grand Canyon has discombobulated this tourist. Unsure of which way he is randomly stumbling, 1/3 of his steps are towards the edge of the cliff, while 2/3 of his steps are towards safety. From where he stands, one step forward will send him tumbling down. What is the probability that he can escape unharmed?

• Simulating Size and Power Using a 10-Sided Die (Star Library)

This group activity illustrates the concepts of size and power of a test through simulation. Students simulate binomial data by repeatedly rolling a ten-sided die, and they use their simulated data to estimate the size of a binomial test. They carry out further simulations to estimate the power of the test. After pooling their data with that of other groups, they construct a power curve. A theoretical power curve is also constructed, and the students discuss why there are differences between the expected and estimated curves. Key words: Power, size, hypothesis testing, binomial distribution

• National Center for Catastrophic Sport Injury Research

As quoted on the site, "The National Center for Catastrophic Sport Injury Research collects and disseminates death and permanent disability sports injury data that involve brain and/or spinal cord injuries." Links to data, annual reports, and definitions of injury are included.
• Practice Questions for Business Statistics

This site offers a list of sample questions that can be used when teaching basic probability concepts, probability distributions, data collection methods, inferential statistics, hypothesis testing, analysis of variance, regression analysis, or problem sensing related to descriptive statistics. Links to the answers are also provided. Application is not limited to business.