# One Numerical Variable Methods

• ### How well can hand size predict height?

This activity is an example of Cooperative Learning in Statistics. It uses student's own data to introduce bivariate relationship using hand size to predict height. Students enter their data through a real-time online database. Data from different classes are stored and accumulated in the database. This real-time database approach speeds up the data gathering process and shifts the data entry and cleansing from instructor to engaging students in the process of data production. Key words: Regression, correlation data collection, body measurements
• ### *Investigating the Modernity of the University Library

This activity makes use of a campus-based resource to develop a "capstone" project for a survey sampling course. Students work in small groups and use a complex sampling design to estimate the number of new books in the university library given a budget for data collection. They will conduct a pilot study using some of their budget, receive feedback from the instructor, then complete data collection and write a final report.
• ### **Simulating Confidence Intervals

This applet generates confidence intervals for means or proportions. The options for confidence intervals for means include "z with sigma," "z with s," or "t." The options for confidence intervals for proportions are "Wald," "Adjusted Wald," or "Score." Users set the population parameters, sample size, number of intervals, and confidence level. Click "Sample," and the applet will graph the intervals. Intervals shown in green contain the true population mean or proportion, while intervals in red do not. The true mean or proportion is shown by a blue line. The applet displays the proportion of intervals containing the population parameter for each sample and a running total of all the samples. Users can also click on a particular interval to display the numerical interval or sort the displayed confidence intervals from smallest to largest. This applet is part of a collection designed to accompany the textbook "Investigating Statistical Concepts, Applications, and Methods" (ISCAM) and is used in Exploration 4.3 on page 327, Investigation 4.3.6 on page 331, and Exploration 4.4 on page 350. This applet also supplements "Workshop Statistics: Discovery with Data," 2nd edition, Activity 19-5 on page 403. Additional materials written for use with these applets can be found at http://www.mathspace.com/NSF_ProbStat/Teaching_Materials/rowell/final/16_cireview_bc322_2.doc and http://www.mathspace.com/NSF_ProbStat/Teaching_Materials/rowell/final/15_sampdistreview_bc322_1.doc.
• ### Primer on Probability, Odds and Interpreting their Ratios

This lecture example discusses calculating chance with probabilities (a ratio of occurrence to the whole) or odds (a ratio of occurrence to nonoccurrence). It presents a clinical example of measuring the chance of initiating breastfeeding among 1000 new mothers. Tables are provided in pdf format.
• ### Primer on Type I and Type II Errors

This lecture example discusses type I and type II errors as they apply in a clinical setting.
• ### Primer on 95% Confidence Intervals

This lecture example reviews the concept of CIs and their relationship to P values. Tables are provided in pdf format.
• ### Primer on Correlation Coefficients

This lecture example discusses how two continuous variables relate to one another with a clinical example of the relationship between body mass and fasting blood sugar. It offers three questions to help readers visualize and interpret correlation coefficients.
• ### Primer on Interpreting Surveys

Because surveys are increasingly common in the medical literature, readers need to be able to critically evaluate the survey method. Two questions are fundamental: 1) Who do the respondents represent? 2) What do their answers mean? This lecture example discusses survey sampling terms and aspects of interpreting survey results.
• ### Parametric and Nonparametric Statistics

This page discusses the differences in parametric and nonparametric tests and when to use then.
• ### Index to Statistics Tutorials

This collection of tutorials covers many statistical applications such as Pearson's Correlation Coefficient, Simple Linear Regression, One and Two Sample t-tests, Paired t-test, One-way Analysis of Variance (ANOVA), Mann-Whitney Test, Kruskal-Wallis Test, Friedman's Test, Interpreting p-values, Comparing two groups, Parametric and Nonparametric analyses, and Multiple Comparisons. The tutorials refer to the WINKS statistical software program, but they are useful for those who do not have access to WINKS.