Sampling and Data: Data Collection Lab I 1.6 2008/03/31 10:18:36 GMT-5 2008/07/08 20:44:38.671 GMT-5 Barbara Illowsky cnx@cnx.org Susan Dean cnx@cnx.org Connexions cnx@cnx.org cumulative data frequency relative sampling statistics systematic This lab allows students to practice and demonstrate techniques used to generate systematic samples. Students will have the opportunity to create relative frequency tables and interpret results based on different data groupings. Note: This module is currently under revision, and its content is subject to change. This module is being prepared as part of a statistics textbook that will be available for the Fall 2008 semester. Class Time: Names:
Student Learning Outcomes The student will demonstrate the systematic sampling technique. The student will construct Relative Frequency Tables. The student will interpret results and their differences from different data groupings.
Movie Survey Ask five classmates from a different class how many movies they saw last month at the theater. Do not include rented movies. Record the data In class, randomly pick one person. On the class list, mark that person's name. Move down four people's names on the class list. Mark that person's name. Continue doing this until you have marked 12 people's names. You may need to go back to the start of the list. For each marked name record below the five data values. You now have a total of 60 data values. For each name marked, record the data: __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________ __________
Order the Data Complete the two relative frequency tables below using your class data. Frequency of Number of Movies Viewed Number of Movies Frequency Relative Frequency Cumulative Relative Frequency 0 1 2 3 4 5 6 7+
Frequency of Number of Movies Viewed Number of Movies Frequency Relative Frequency Cumulative Relative Frequency 0-1 2-3 4-5 6-7+
Using the tables, find the percent of data that is at most 2. Which table did you use and why? Using the tables, find the percent of data that is at most 3. Which table did you use and why? Using the tables, find the percent of data that is more than 2. Which table did you use and why? Using the tables, find the percent of data that is more than 3. Which table did you use and why?
Discussion Questions Is one of the tables above "more correct" than the other? Why or why not? In general, why would someone group the data in different ways? Are there any advantages to either way of grouping the data? Why did you switch between tables, if you did, when answering the question above?