3.1 Estimators

Justify why an estimator is or is not unbiased.

• When estimating a population parameter, an estimator is unbiased if, on average, the value of the estimator does not underestimate or overestimate the population parameter.

Calculate estimates for a population parameter.

• A sample statistic is a point estimator of the corresponding population parameter and can be thought of as the estimate of the population parameter. For example, the sample proportion p is a point estimator for the population proportion p.