In a perfect world, we want the sample to be representative of the population. If it were in fact perfectly representative, we might call it a representative sample, because the information we collect about the sample would “scale up” to the population.
Read MoreA sample mean or sample proportion might be a great estimate of the population parameter, or it might be a really bad estimate. So it would be really helpful to be able to say how confident we are about how well the sample statistic is estimating the population parameter, and that’s where confidence intervals come in.
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