12.1 Sampling Techniques and Misuses of Statistics 767 Exercises Warm Up Exercises In Exercises 1–10, fill in the blank with an appropriate word, phrase, or symbol(s). 1. The art and science of gathering, analyzing, and making inferences (predictions) from numerical information obtained in an experiment is called _________. Statistics 2. Making generalizations or predictions from the data collected is called _________ statistics. Inferential 3. The collection, organization, and analysis of data is called _________ statistics. Descriptive 4. All items or people of interest in an experiment are collectively called a(n) _________. Population 5. A subset of a population used by statisticians to make predictions about a population is called a(n) _________. Sample 6. When a sample is obtained by drawing every nth item, the sample is called a(n) _________ sample. Systematic 7. If a sample is drawn in such a way that each time an item is selected, each item in the population has an equal chance of being drawn, the sample is called a(n) _________ sample. Random 8. A sample that consists of a random selection of groups or units is called a(n) _________ sample. Cluster 9. When a population is divided into parts, called strata, for the purpose of drawing a sample, the procedure is known as _________ sampling. Stratified 10. A sample that uses data that are easily or readily obtained is called a(n) _________ sample. Convenience Practice the Skills/Problem Solving Sampling Techniques In Exercises 11–20, identify the sampling technique used to obtain a sample. 11. TV Viewers Viewers of Hulu are classified according to age. A random sample of viewers from each age group is selected. Stratified sample 12. Assembly Line Every 10th refrigerator coming off an assembly line is checked for defects. Systematic sample 13. Selecting Zip Codes A state is divided into zip codes. A random sample of 12 zip codes is selected. A random sample from each of the 12 selected zip codes is selected. Cluster sample 14. Door Prize A door prize is given away at a home improvement seminar. Tickets are placed in a bin, and the tickets are mixed up. Then a ticket is selected by a blindfolded person. Random sample 15. Buying Tickets Every 20th person in line at a consession stand is asked their age. Systematic sample 16. Town Services The Oneida town supervisor wants to determine residents’ opinions regarding town services. She divides the residents into three income classes: workingclass households, middle-class households, and upperclass households. She then takes a random sample of households from each income class. Stratified sample 17. Listeners Opinions A radio station DJ asks her listeners to call in their opinions regarding a new song. Convenience sample 18. Customers Opinions To determine customer opinion of its carry-on luggage policy, American Airlines randomly selects 50 flights and surveys all passengers of those flights. Cluster sample 19. Satisfaction Survey The manager at Planet Fitness wants to administer a satisfaction survey to its current members. Using its membership roster, the manager randomly selects 40 members and sends them an email with a link to an online survey. Random sample 20. Voting The Student Senate at the University of North Carolina is electing a new president. The first 25 people leaving the library are asked for whom they will vote. Convenience sample SECTION 12.1 Wavebreak Media Ltd/123RF Charnsitr/Shutterstock
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