Introduction Suppose that we are going to find out how many of the audience of the ‘Real Madrid vs. Barcelona’ match that was conducted on October 2014 like Lionel Messi the most and how many of them bet on Neymar Júnior as the best footballer in the world. It is a herculean task to collect the exact data by assessing the views of all the 400 million audience.
Suppose you have to run a survey about the coffee drinking habits of high school students of USA. The population of the students is about 4 million. You can not even imagine running the survey by asking each and every student to get the relevant data because of requirement of huge amount of time, money and other resources. The cost of the survey in this case would be too monumental to justify the effort. To solve these types of problem, sampling can be used.