What is the formula #("group size")/("total population")times"sample size"# used for?
1 Answer
Oct 18, 2015
To find (approximately!) the number of members of a particular group among all in a sample.
Explanation:
Assume, you know that 180 million of people (group size) out of 300 million who live in the United States (total population) are either working or actively looking for a job.
If you randomly choose a city with a population of 3 million people (sample), how many of them (approximately!) are working or actively looking for a job?
An answer is:
So, you count on (approximately!) 1.8 million people working or actively looking for a job in this city.
