The Syrian hamster has an average life span of two to three years. Although uncommon, these hamsters can sometimes live up to five years. A hamster's life span can be extended to a degree by providing it with a clean environment and fresh food daily. Continue Reading.
and substituting the estimate for gives. which is an unbiased estimator of the variance of the mean in terms of the observed sample variance and known quantities. Note that, if the autocorrelations are identically zero, this expression reduces to the well-known result for the variance of the mean for independent data.
Bias of an estimator. In statistics, the bias (or bias function) of an estimator is the difference between this estimator's expected value and the true value of the parameter being estimated. An estimator or decision rule with zero bias is called unbiased. Otherwise the estimator is said to be biased.