Question

Identify the type of sampling used​ (random, systematic,​ convenience, stratified, or cluster​ sampling) in the situation described below.

A womans selected by a marketing company to participate in a paid focus group. The company says that the woman was selected because every 2500th person in the phone number listings was being selected

Answer 1

Answer:

Systematic sampling.

See explanation below.

Step-by-step explanation:

Since the selection on this case is with a fixed number , for this case every 2500 people in a phone number listing the best opton for this case is systematic sampling.

Teh reason is that by definition systematic sampling is a type of probability sampling method in which "sample members from a larger population are selected according to a random starting point but with a fixed, periodic interval".

For example if we need to select a random group of 1,000 people from a population of 50,000  we can use the random number 50000/1000 =50 to select one person each 50.

So in general if we have a population size N and we want to select n people we can find the random number doing k=N/n.