A researcher always need population to collect sample for research.Identify the

Introduction: Population: In statistics, a population is a grouping of all potential objects, people, events, or other items that share a given attribute and from which data may be gathered to perform an interesting statistical analysis. A sample is a portion of the population that is of interest and contains the population units that are actually taken into account by the statistical analysis. Since it is frequently too challenging, impractical, or impossible to include the entire population in the statistical study of interest, a sample is used instead.

The aim of the hospital administrator is to determine whether the rate of absenteeism is greater for single parents or parents who are not single, among those working in the hospital. Clearly, a comparison is to be made between the two groups- “single parents” and “parents who are not single” of the hospital employees. Thus, it is suitable to treat each group as a separate population in itself. Here, there are two mutually exclusive and exhaustive populations among parents working at the hospital. One population consists of all single parents working at the hospital. The other population consists of all other parents working at the hospital, who are not single. Since the decisions have to be made for the employees at the hospital, and not for a general or larger population, assuming that the number of parents working at the hospital (single or otherwise) is not too large, it would be advisable to use both the populations for the study, instead of resorting to sample surveys. However, due to various constraints, sample survey might be the only feasible solution. In order to avoid any kind of bias while including employees in the study, a random sample of a suitable size can be taken from the population of all single parents working at the hospital, and independently, a random sample of a comparable size can be taken from the population of parents who are not single and working at the hospital. Then, the researcher may separately find the rates of absenteeism for the two samples, and compare them, in order to conclude about the population. One might use stratified sampling by first dividing the population of all parents working at the hospital into two strata- those who are single, and those who are not. The researchers can find the ratio of parents who are single, to those who are not single, in the entire population of all hospital employees; then, they can decide upon a suitable sample size, and take samples from the two populations in the same ratio as in the population. This would ensure a good representation of both the populations in the sample. 

As in the previous question, here are two groups to be compared- men and women. We have assumed that the marketer is interested in the adults of the country, and not in minors, or in people of other countries. As the researcher is not mentioned to be interested about a particular group of men and women, but rather, about men and women in general, there are two populations- men in the country, and women in the country. Note that people who are not adults are generally not referred to as “men” and “women”, so all people who are not adults may be ignored. However, if one wishes to know about the men and women of the entire world and not just in the country, then the two populations to be considered are- men in the world, and women in the world. It might be difficult to get a random sample from all men and women in the country. As a result, can use a suitable for of convenience sampling for this study. They may select a few localities of their choice, wait around in the streets, and men and women approaching that part of the street, relevant questions to assess their product knowledge of cars. In order to add a random element to their study, they may first general a random number; say for example, the random number is 3. The researcher can then stop the third person approaching the part of the street, them the research questions, and note their gender. Thereafter, they may repeat this with every passer-by coming at a particular interval, say, every 7-th passer-by thereafter. At the end of the study, the researcher may assess the responses of the sampled individuals, and compare the performances of the men with those of the women.