what is population 
population is a statistical term that designates the pool from which a sample is drawn for a study any selection grouped by a common feature can be considered a population a sample is a statistically significant portion of a population understanding populationsstatisticians scientists and analysts prefer to know the characteristics of every entity in a population to draw the most precise conclusions possible this is impossible or impractical most of the time however because population sets tend to be quite large a sample of a population must usually be taken because the characteristics of every individual in a population can t be measured due to constraints of time resources and accessibility the term individual doesn t always mean a person in statistics an individual is a single entity in the group being studied there s no real way to gather data on all the great white sharks in the ocean which is a population finding and tagging each one isn t feasible marine biologists instead tag the great whites they can as a sample they begin collecting information on them to make inferences about the entire population of great whites this is a random sampling approach because the initial encounters with tagged great whites are entirely random a valid statistic can be drawn from either a sample or a study of an entire population the objective of a random sample is to avoid bias in the results a sample is random when every member of the whole population has an equal chance to be selected to participate 1