Statistical Methods

Unit 3 - Estimation

3.5.Unbiased Estimator
An estimator is said to be unbiased if the average of all values taken by the estimator is equal to the population parameter
For example: Sample mean is an unbiased estimator population mean because average of all means of samples of same size taken from a population is equal to the population mean.
Similarly, Sample proportion is the unbiased estimator of population proportion and Sample variance is the unbiased estimator of population variance.
Note :
Sample variance is given by,