NATS 1500 Lecture Notes - Lecture 11: Simple Random Sample, Confidence Interval, Sampling Frame
4 Oct 2016
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Document Summary
Margin of error getting slightly less or slightly more than the number expected. It reflects and takes into account the random variability you would get from sampling a different sample (from sample to sample) Approximately plus or minus two standard deviations. Will bounce around covering about 95% of the standard deviation missing about 5% of the value. The error that comes from randomness from sampling - but it doesn"t tell us about the randomness caused by other and maybe external sources, for example bias in the samples. Professor talks about the example of flipping a coin; your sample will have a variance because it"s nearly impossible for the coin to flip both heads and tales equally. Depends on the size of the sample, not the size of a population (india example) which resulted in the random variability. Simple random sample (srs) ha to give everyone in the population the same opportunity in getting in the sample.
