Which of the following Sampling Method is Based on Probability

(A) Convenience Sampling

(B) Quota Sampling

(C) Judgement Sampling

(D) Stratified Sampling

Answer : (D)

Explanation : Probability means the chance of happening or not happening of any event. For example, have 100 tickets in the box. In hundred tickets, one ticket is of Rs. 10,00,000, price. If we will mix and take a ticket through random sampling, it will be based on the probability because, there is only 1% chance of coming the winning ticket. In stratified sampling, we use random sampling. First of all, we classify the whole group in small parts. Now, we calculate the % proportion of each sub-group in the whole group. Now, sample is taken from each sub-group on the basis of random sampling. For example, there are 100 students in the class,  50 are the boy with the age below 20 and 30 are the boy between 20-25 age. 20 are girls. Now, we have to give gift to 10 students on the basis of stratified sample.

we will divide 10 students sample on the proportion

50/100 X 10 = 5 students will be boy with the age below 20, will get gift.

30/100 X 10 = 3 Students  will be boy between the age 20-25 , will get the gift.

20/100 X 10 = 2 students will be girl, will get the gift.

So, out of 50 boys with the age below 20, we have to choose just 5 students. We will write the name of all 50 students in the tickets and then mix and keep in the box. Now, we will take 5 tickets by closing our eyes. So, it is the probability of coming any student = 5/50 X 100 = 10%. So, in end, we say that only stratified sampling method is based on probability.