For a hypothetical experiment involving algebra students, the population of interest must first be defined. A broad population, such as 'all algebra students,' is often too large for a study. Therefore, it is narrowed to a more specific and manageable group, like 'all algebra students in a particular city.' To ensure the sample is representative, it should include students from diverse backgrounds, encompassing various income levels, family situations, races, ethnicities, religions, and geographic locations. From this more focused population, a random sample, for instance of 200 students, can be selected for the experiment.