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Sun 26 Jul, 2015 04:28 pm
assume we want to estimate the mean cost of computer repairs for the population of consumers. How many consumers randomly selected for the survey if we want to be 95% confident that the sample mean is within $2 of the population mean?
(margin of error e=2, a=0.5, o=12 and za/2 = 1.96
@akohn,
It depends on what the standard deviation of the population is.
1.96 Standard deviation / sqrt (Sample Size) = 2 so the sample size will be approximately the square of the standard deviation.
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