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st095 18_s_Random selection

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    So, the first one is random. We assign a unique number, 1 to n, to each object.
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    And then, we randomly choose numbers from 1 to n. This results in every object
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    in the population having an equal chance of being selected. The second one's
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    kind of tricky. We don't know for sure if it's random because we don't know if
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    we randomly assigned a unique number. We have to make sure that if we're going
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    to give each object a number, it has to be randomly assigned, and each object
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    has the same chance of getting any number. This one, we took care of that. We
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    randomly assigned a unique number, and then we chose multiples of six. Now, this
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    choosing multiples of six might throw you off a little bit, because that doesn't
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    seem random. But, every object in the population has an equal chance of being a
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    multiple of 6. And finally, this one is also random. This one's actually called
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    stratified sampling, because we divided the population into subpopulations, in
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    this case two. And, every object in the population had an equal chance of being
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    in either one of the subpopulations. And then, random samples were taken from
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    each group, so this is also random. So yay, you're done with Lesson 1. Moving
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    onto the problem set.
Cím:
st095 18_s_Random selection
Video Language:
English
Team:
Udacity
Projekt:
ST095- Statistics
Duration:
01:21
Cogi-Admin edited Angol subtitles for st095 18_s_Random selection
Cogi-Admin edited Angol subtitles for st095 18_s_Random selection
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