Types Of Estimates | Estimator And Estimates

Types Of Estimates

We can make two types of Estimates about a population: a point estimate and an interval estimate.

A point estimate is a single number that is used to estimate an unknown parameter.
If, while watching the first members of a football team come onto field, you say " why, i bet their line must avarage 250 pounds," you have made a point estimate here.
An Interval estimate is a range of values used to estimate a population.
It indicates the error in two ways: by the extent of its range and by the probability of the true population parameter lying within that range. In this case, the department head would say something like," I estimate the true enrollment in this course in the fall will be between 330 and 380 and that it is very likely that the exact enrollment will be fall within this interval.

Estimator and Estimates

Any sample statistic that is used to estimate a population is called an Estimator, that is an Estimator is a sample statistic used to estimate a population parameter.
When we have observed a specific numerical value of our estimator, we will call that value an estimate. In other words, an estimate is a specific observed value of a statistic.