Question

In the following sentences determine the appropriate sampling A, B, C or D

A --- RANDOM (SIMPLE RANDOM SAMPLING)
B --- SYSTEMATIC
C --- STRATIFIED
D --- Cumulative (CONGLOMERATES)

1- A company is divided by DIRECTIVES, EMPLOYEES, SECRETARIES AND WORKERS. It is wanted to make a study to know the level of satisfaction in relation to the benefits that the company has. The head of human resources decides to take a random sample of each category.

2- A university career has “N” students identified in an easy way, the director wants to see the opinion regarding the enrollment process, decides to start in tenth of the entire list and take the sample every 30 items on the list.

3- A university career has “N” students identified per semester (first semester, second semester, ..., ninth semester in an easy way, the principal wants to see the opinion regarding the enrollment process, decides to select 2 semesters and survey all .

4- A university degree has “N” students identified in an easy way, the principal wants to see the opinion regarding the enrollment process, decides to use a random digit table to obtain the sample.

Answer 1

Solution:

1) For the given scenario "Stratified Sampling" will be appropriate. We use stratified sampling when our population is heterogeneous. In stratified sampling we divide the whole population in several homogeneous strata (groups) then we randomly select sampling units from each stratum (group). Here, also company is divided into several stratas likes "DIRECTIVES, EMPLOYEES, SECRETARIES AND WORKERS" and then human resources decided to take random sample from each of the categories. Hence, stratified sampling will be appropriate here.

2) For the given scenario " Systematic Sampling" will be appropriate. In systematic sampling we select sampling units starting from any random point and then every k^{​​​​​​th} unit after that. This "k" is known as sampling interval and obtained by dividing population size with sample size i.e. k = N/n where, N is population size and n is sample size. We choose the starting point randomly by choosing any point between 1st unit and k^{​​​​​​th} unit. Here also director decides to start in tenth of the entire list and take the sample every 30 items on the list, it means director's starting point is 10th unit and then he chooses every 30th sampling unit after that. Hence, systematic sampling will be appropriate here.

3) For the given scenario "Cumulative (Conglomerate) sampling" is appropriate. The standard term is "Cluster sampling". In this type of sampling, population is divided into several groups known as clusters. We randomly select groups from these clusters (groups) and then we take random sample from each selected group. Here also population is divided into semesters (from 1st to 9th) and director want to select any two semesters randomly. Hence, Cumulative (Conglomerate) sampling will be appropriate here.

4) For the given scenario "Simple random sampling" is appropriate. In simple random sampling we select sampling units in such a way that each sampling unit has an equal chance of being included in the sample. It means that probability of each sampling unit being included in the sample is same. We can draw simple random sample with the help of random digit table. The samples drawn using random digit table are simple random sample. Here also our population size is N and we want to draw random sample using random digit table. Hence, simple random sampling is appropriate here.