Question 1194546: Determine the type of sampling from the given situation.
1. The author of the statistical study was an observer at a police sobriety checkpoint at which every 5th driver was stopped and interviewed.
2. A researcher for Faithy Athletic equipment company is studying relationship between level of education and participation in any sport. She conducts a survey of 40 randomly selected golfers, 40 selected tennis players and 40 selected swimmers.
3. Indicate if it refers POPULATION or SAMPLE , the yearly expenditures produced by a factory in three weeks.
Answer by math_tutor2020(3817)   (Show Source):
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Answers:- Systematic Sampling
- Stratified Sampling
- I'm not sure what your teacher is asking here. Sorry about that. I would get another opinion from another tutor.
Explanation:
Systematic sampling is when we set up a strict well defined rule how to gather members of a sample. Usually it's something like "every 5th person" or something along those lines. There is probably some slight bias here, but it definitely beats convenience sampling which has more bias.
Stratified sampling occurs when we break the population into various groups known as strata. Think of it like having people in various rooms of a house. Then select representative members from each room to form the sample. This guarantees the entire house is represented fairly. Keep in mind that we can't have any groups overlap. This means that a person is either a golfer, a tennis player, or a swimmer, but not a combo of those items.
Another example of stratified sampling is having congress members from each state in the US. Each congress member represents his or her state to ideally provide the most fair unbiased sample possible.
Of course this technically isn't random since people have to volunteer to run, have the money to do so, have the willpower & knowledge (and a bit of luck) to get elected. But hopefully you get the idea of what I mean.
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