Simple Random Sampling

摘要: When a census of the entire population interest is difficult to obtain, sample often used. There are many sampling designs that can be used obtain would hopefully representative population, and among these designs, several allocate same inclusion probability each unit in population. If has all units independent, then we have simple random sample. Another way formulate this state consisting given number becoming selected sample. Keywords: population; sampling design; sampling frame; sampling with replacement; sampling without replacement