2. Vocabulary: Statistics – a study of how to collect, organize, analyze, and interpret numerical information from data Individuals – the people or objects included in the study Variable – characteristic of the individual to be measured and observed Quantitative – has a value or numerical measurement for which operations make sense (addition or averaging) Qualitative – describes an individual by placing into a category or group **Mt. Everest

3. Data: 2 types Population data – the data are from every individual of interest would collect data from ALL individuals who have climbed Mt. Everest Sample data – the data are from only some of the individuals of interest would collect data from just SOME of the climbers

4. Example 1: The Hawaiian Department of Tropical Agriculture is conducting a study of ready-to-harvest pineapples in an experimental field. individuals? possible variable? quantitative or qualitative? data type? another possible variable? quantitative or qualitative? pineapples weights – specify units of measure quantitative it depends taste qualitative – place into categories

5. Levels of Measurement - another way to categorize data -indicates the type of arithmetic that is appropriate for the data Nominal – applies to data that consists of names, labels, or categories; no way to order from smallest to largest Ordinal – applies to data that can be arranged in order; differences between data cannot be determined or are meaningless Interval – applies to data that can be arranged in order; difference between data are meaningful (ex. Temperature) Ratio – applies to data that can be arranged in order; both differences and ratios between data are meaningful (have a true zero)

6. Example 2: a) Taos, Acoma, Zuni, and Cochiti are the names of four Native American pueblos from the population of names of all Native American pueblos in Arizona and New Mexico Nominal b) In a high school graduating class of 319 students, Jim ranked 25 th, June ranked 19 th, Walter ranked 10 th, and Julia ranked 4 th, where 1 is the highest rank Ordinal

7. Example 2 (cont’d) : c) Body temperatures (in degrees Celsius) of trout in the Yellowstone River Interval (for Celsius-scale temps, there is not an inherent starting point/true zero) d) Length of trout swimming in the Yellowstone River Ratio (an 18-in trout is 3 times the length of a 6-in trout)

8. Looking ahead… Two branches of statistics: Descriptive – involves methods of organizing, picturing, and summarizing information from samples or populations Inferential – involves methods of using information from a sample to draw conclusions regarding the population (useful when the population is too large to measure)

9. Homework Section 1.1 Problems p. 10 – 11 #1 – 9 all