**Estimator: Definition**

**An estimator is defined as a sample statistic which is used to measure the population parameter. E.g. sample mean can be a sample statistic which is used to measure the population mean µ.**

**Estimate: Definition**

**Specific Observed Value of an estimator is known as the estimate. E.g. an estimate is formed from a sample of 120 students in a school and the mean weight of the sample comes out to be 55 kg, now if we use this statistic is used to estimate the population of all the students of that school then the sample statistic of 55 kg will be the estimate for the population mean of all the students of that school.**

**Importance of Estimation:**

**If the mean salary of a region is to be found, it is not feasible for a researcher or statistician to collect the report for each member of the region and then to compute the mean. Instead a sample is collected and the mean is collected for that sample which is used to infer about the population. This is estimation and without estimation from the sample one has to study the population to infer about which is not possible for a large sample. Hence the study of estimation is necessary. In this section we will only consider “Point Estimation”.**