Do Now Prob & Stats 8/26/14 What conclusions can you draw from this bar graph?

Transcription

1 Do Now Prob & Stats 8/26/14 What conclusions can you draw from this bar graph?

2 Probability & Statistics Section 1 1 What Is Statistics?

3 Vocabulary: Statistics: the science of collecting, organizing, summarizing, and analyzing information in order to draw conclusions; the study of how to collect, organize, analyze, and interpret numerical information from data Individuals: the people or objects included in the study

4 Variable: the characteristic of the individual to be measured or observed Quantitative Variable: has a value or numerical measurement; operations such as addition or averaging make sense Qualitative Variable: describes an individual by placing them into a category or group (such as male or female)

5 Population: the group to be studied; the variable is from EVERY individual of interest Sample: a subset of the population; the variable is from only some of the individuals of interest

6 Branches of Statistics Descriptive: organizes and summarizes the information collected Inferential: uses information from a sample to draw conclusions regarding the population

7 Parameter: a characteristic or measure obtained by using all the data values for a specific population Statistic: a characteristic or measure obtained by using the data values from a sample

8 Examples: Determine if each example would describe a population, sample, individual, variable, parameter, or statistic 1. the average test score for all students in a statistics class 2. a farmer randomly selects 100 soybean plants from his crop to measure the weight of the soybeans 3. each car in a study of the population of all 2007 Ford Escapes 4. people 18 years or older in the United States 5. the average income of 50 randomly selected families in Harrisburg 6. the weight of each car in a study of the population of all 2007 Ford Escapes

9 Levels of Measurement Nominal (in name only) Qualities with no ranking/ordering No numerical or quantitative value Data consists of names, labels, categories Example: car colors (red, blue, silver, etc.), ZIP codes, gender

10 Levels of Measurement Ordinal Can be arranged in some order, but the differences between the data values are meaningless Each data value can be compared with another Example: textbook ratings (poor, fair, good, new), Judging (1st, 2nd, 3rd)

11 Levels of Measurement Interval Values can be ranked and differences are meaningful No intrinsic zero (or starting point) Example: temperatures (in Fahrenheit or Celsius), SAT scores

12 Levels of Measurement Ratio Values can be ranked and differences are meaningful There is a true zero, or starting point Can say things like one value is twice as large as another Example: height, weight, salary, age

13 Classify each as nominal level, ordinal level, interval level, or ratio level of measurement. 1. Rating of movies as G, PG, and R 2. Number of candy bars sold on a fund drive 3. Classification of automobiles as subcompact, compact, standard, and luxury 4. Temperatures of hair dryers 5. Weights of suitcases on a commercial airliner

14 Classify each as nominal level, ordinal level, interval level, or ratio level of measurement. 6. Rankings of golfers in a tournament 7. Salaries of the coaches in the NFL 8. Categories of magazines in a physician s office sports, news, men s, health, etc. 9. Ages of children in a day care center 10. Temperatures inside 10 pizza ovens

15 Homework: pg #1 9