1. Statistics

2. Our objective today: Learn about statistics and why they are important Explore how we can gain information about a population by examining a sample population Statistics

3. Statistics is the study of the collection, organization, analysis of data. Statistics

4. A statistical population is a set of entities concerning which statistical inferences are to be drawn. Examples: Population of a school A sports team Statistics

5. A statistical sample is a subset of the statistical population that should represent the statistical population. A sample is valid only if the sample is representative of the population Statistics

6. Random sampling tends to produce representative samples and support valid inferences. Statistics

7. Variability – a measure of how far a set of numbers is spread out. Measures of Central Tendency – relates to the way in which data tends to cluster around some value Mean Median Mode Range Statistics

9. http://www.youtube.com/watch?v=qpxtBghmvvs

10. Data Set: 11, 26, 22, 15, 18, 26, 16 Mean Median Mode Range

11. Data Set: 5, 12, 6, 15, 7, 10, 4, 8 Mean Median Mode Range

12. http://www.youtube.com/watch?v=1jVZi0cNHls

13. Can you think of any ways that Statistics are used in life? Statistics

14. Can you think of data distributions and statistics kept in sports? Who cares about these? Would variability matter in Tim Duncan’s earnings? CAN YOU THINK OF OTHER SPORTS STATISTICS ? Statistics

17. Statistics & Probability

18. Can you think of data distributions and statistics kept for music? Who cares about these? Would variability matter in Rihanna’s statistics? Statistics

19. Can you think of data distributions and statistics kept that will effect your application to college? Who cares about these? Would variability matter ? Statistics

20. Statistical Data can be 1. Categorical 2. Numerical Statistics

21. Categorical Data – data that fall into specific labels or categories. Categorical data is data that is defined by words or as a limited number of answer options. Statistics

22. GreenYellowOrangeBlueBrownRedTotal Number51444191258 Percent Categorical data is reported in the FREQUENCY. It is recorded by how many or what percentage fall into each category. For example, if you counted the number of each color of M&Ms found a bag, you may find.

23. Statistics GreenYellowOrangeBlueBrownRedTotal Bag 151444191258 Bag 251527 1054 Bag 331355191055 If you counted several bags, you might find.

24. Statistics This data can also be reported in other forms, such as bar graphs that show the frequency. What patterns do you see?

25. Statistics GreenYellowOrangeBlueBrownRedTotal Number92449109905764151,731 Percent The following is actual data of colors found in a sampling of 30 bags of M&Ms. Find the percentage of each color. Sketch a bar graph showing the percentages.

26. Statistics Do you think the sample of 30 bags have any more statistical reliability than the earlier sample of 3 bags? 30 Bags – Percent of Each Color 40% 35% 30% 25% 20% 15% 10% 5% 0% Green Yellow Orange Blue Brown Red

27. Numerical Data – data that are counts or measures. For example, we count people to find the population of each state in the United States in order to answer the question, “How much do state populations vary in size?” Statistics

28. What are other examples of numerical data?

29. Statistics In decade from 1901 to 1910, how many immigrants came from Europe? What else can you say about this decade? Decade Immigrants From Europe Total Immigrants Percent of Immigrants From Europe 1881–18904,735,4845,246,61390% 1891–19003,555,3523,687,56496% 1901–19108,056,0408,795,38692% 1911–19204,321,8875,735,81175% 1921–19302,463,1944,107,20960% 1931–1940347,566528,43166% 1941–1950 621,1471,035,03960% 1951–19601,325,7272,515,47953% 1961–19701,123,4923,321,67734% 1971–1980 800,3684,493,31418% 1981–1990 761,5507,338,06210% 1991–20001,359,7379,095,41715%

30. Categorical vs. Numerical ? Age Month you were born. Weight Favorite Singer Eye Color Height Favorite Ice Cream Statistics

31. The school food service wants to increase the number of students who eat lunch in the cafeteria. The student council has been asked to conduct a survey of the student body to determine the students’ preferences for hot lunch. They are considering several methods to do the survey. Statistics & Probability

32. Let’s look at the methods and determine if they would provide a random sample. Which method should the council use? 1. Write all the student’s names on cards and pull them out in a draw to determine who will complete the survey. 2. Survey the first 20 students that enter the lunchroom. 3. Survey every 3 rd student who gets off a bus. Statistics

33. Now, let’s devise a sampling method in our class for conducting the following surveys. 1.Do 7 th Grade Students prefer Coke or Pepsi products ? 2.What is the average shoe size for students at Quail Hollow? Statistics