Guest
OK great let's continue by introducing the concept of an estimator of a population parameter. It is an approximation depending solely on sambil information a specific value is called an estimate. There are two types of estimates point estimates and confidence interval estimates a point estimate is a single number. While a confidence interval naturally is an interval the two are closely related. In fact the point estimate is located exactly in the middle of the confidence interval. However confidence intervals provide much more information and are preferred when making inferences. Don't worry we will have separate lessoned dedicated to confidence intervals. All right have we seen estimates so far. Sure we have the sample mean X bar is a point estimate of the population mean you. Moreover the sample variance as squared was an estimate of the population variance Sigma squared. There may be many estimators for the same variable.
