Sampling strategies. A statistics student who is curious about the relationship between the amount of time students spend on social networking sites and their performance at school decides to conduct a survey. Various research strategies for collecting data are described below. In each, name the sampling method proposed and any bias you might expect.
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He randomly samples 40 students from the study’s population, gives them the survey, asks them to fill it out and bring it back the next day.
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He gives out the survey only to his friends, making sure each one of them fills out the survey.
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He posts a link to an online survey on Facebook and asks his friends to fill out the survey.
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He randomly samples 5 classes and asks a random sample of students from those classes to fill out the survey.