given data and told to calculate mean and standard deviation. for 12 individuals. then it says it is proposed that 500 individuals are usedin a full study. comment on the expected changes in the mean and standard deviation of the values in the full study.
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The mean would on average be the same. The sample mean is an unbiased estimator of population mean.
The standard deviation of the 500 would (on average) be larger than that of the 12. Standard deviation is a biased estimator. You could reduce this bias by using the "n-1" standard deviation as it is an unbiased estimator.
The standard deviation of the 500 would (on average) be larger than that of the 12. Standard deviation is a biased estimator. You could reduce this bias by using the "n-1" standard deviation as it is an unbiased estimator.