Answer:
Correct option is D.
Explanation:
Random sampling implies the selection of of values or individuals in a random pattern.
A stratified random sampling is a sampling method where:
- First divide the entire population into homogeneous subgroups, known as strata.
- Then take a random sample form each of the strata such that the sample size is proportional to the size of the strata.
In this case the it is provided that the population consists of 30 members, 10 under the age of 25 and 20 over the age of 25.
So the stratas are:
- 10 members under the age of 25.
- 20 members over the age of 25.
Now to a random sample of size 2 is selected from strata 1 and a random sample of size 4 is selected from strata 2.
This forms a stratified random sample.
Correct option is:
A population contains 10 members under the age of 25 and 20 members over the age of 25. The sample will include two people chosen at random under the age of 25 and four people chosen at random over 25.