Final answer:
Sampling is the process of gathering information from a small part of a population to make inferences about the entire population. Researchers use sample data because it is impractical to collect data from every member of a population. By using a representative sample, accurate estimates and generalizations about the population can be made.
Step-by-step explanation:
Sampling is the process of gathering information from a small part of a population in order to make inferences about the characteristics of the entire population. Researchers use sample data instead of population data because it is often impractical or impossible to collect data from every member of a population. By using a representative sample, researchers can make accurate estimates and generalizations about the population. For example, if a researcher wants to determine the average height of all students in a school, it would be more feasible and cost-effective to measure the heights of a sample of students rather than the entire student population.