Introduction to Sampling Theory Population and Random Sample Population and Random Sample Remarks: While in theory a random sample X"could generate many different data sets x",each with size n,one may only observe or obtain one data set x"in practice.This is the case with Examples 6.2 and 6.3 which are called time series data. For example,if we would like to obtain another data set for the Chinese GDP growth rate,we would have to let the Chinese economy repeat again back from 1953,and this is simply impossible due to the non-experimental nature of a real economy. Introduction to Sampling Theory Introduction to Statistics and Econometrics April 16,2020 9/167Introduction to Sampling Theory Introduction to Sampling Theory Introduction to Statistics and Econometrics April 16, 2020 9/167 Population and Random Sample Population and Random Sample Remarks: