What does it mean to say that a sample statistic is an unbiased estimator of a population parameter?

Select ALL that apply.

A

It means that a statistic calculated from any type of sample will be the same value as the parameter being estimated.

B

It means that the expected value (mean) of all possible observations of an unbiased sample statistic is equal to the population parameter being estimated.

C

It means that the average of the squared deviations from the sample mean equals the population variance.

D

It means that the mean of one sample is an unbiased estimator of the mean of any similar population.